Concentrating solar-electric generator

FIELD: solar-electric power supplies; modular solar-electric generators for space vehicles.

SUBSTANCE: proposed solar generator module has at least one cellular-structure panel 1 incorporating front face sheet, rear face sheet, and cellular lattice in-between. Front sheet mounts alternating rows of solar cells 2 and wedge-shaped reflectors 3. The latter may be of developable type, for instance made of thin film stretched on stiff frame which do not cover solar cells 2 in folded condition. One of generator-module design alternates may have additional cellular-structure lattice attached to rear face sheet. At least one of face sheets is made of polymer incorporating high-heat-conductivity threads positioned in average perpendicular to longitudinal axis of rows of solar cells 2. Module may incorporate at least two hinged cellular panels folded along hinge whose reflectors 3, for instance non-developable ones, are alternating in folded condition without contacting each other. Panel mechanical design affords maintenance of uniform sun radiation distribution among all cells of generator module at small deviations from sun rays. Reflectors may be covered with aluminum layer or better silver one applied by vacuum evaporation and incorporating additional shield.

EFFECT: reduced space requirement, enhanced strength and stiffness of generator panel, reduced mass of passive structure, improved heat transfer from working components of panel.

17 cl, 16 dwg

The present invention relates to a solar generator, in particular for space solar generator, used to generate solar panels.

On spacecraft (CLA) as the primary energy source used, as a rule, solar cells, which have and are oriented so that they perceived the solar radiation.

On KLAH with stabilization of the body in space solar cells are usually in the form of a series of planes and placed on the solar wings extending from opposite sides of the body of KLAH. Preferably, the solar wings could turn to support them to the extent possible, perpendicular to the solar radiation. Because solar wings in a deployed position have a relatively great length, they are formed as a rule from the set of planar solar panels, which are connected to each other or "accordion" (one-dimensional deployment)or in the form of "pavers" (two-dimensional deployment)in order to ensure the possibility of their compact styling when you start KLAH.

The number of solar cells installed on KLAH, depends on the estimated needs of KLAH in energy and efficiency of solar cells. The use of solar cells with high efficiency allows to reduce the total number of items necessary for this particular DRINK, but they are extremely expensive. Given that increasing the number of solar cells increases their weight and associated costs, there is great interest in reducing the number of elements to be installed on KLAH.

Therefore, this research effort were designed to concentrate solar radiation on the solar cells through the use of reflective surfaces, which are located next to the solar panels and oriented in such a way that reflect on these elements additional radiation. Thanks to solar radiation, which otherwise would pass by solar wing, changes direction, which again falls on the solar cells. Despite the fact that the efficiency of a solar cell to convert this additional reflected radiation into useful energy, typically less than in the case of directly incident radiation (mainly due to the temperature increase of the element, and an acute angle of incidence), the concentration of solar energy can significantly reduce the number of installed on KLAH solar cells and, consequently, to achieve savings in weight and cost of KLAH. For concentration of solar radiation were offered both hard and flexible reflectors, the ri this second advantage is the reduced weight. For example : design of a flexible reflector described in U.S. patent No. 6017002 and 6050526, and hard in U.S. patent No. 5520747.

Although these reflect the design and ensure the concentration of solar radiation, their placement next to the solar panel has a number of negative phenomena.

So, there is an increase in temperature of the solar cell and, consequently, decreasing the efficiency of energy conversion. In addition, errors in pointing are due to lack of uniformity of flow on the solar panel, as well as more complex power system control, which leads to a reduction of the produced electrical power panel.

In the case of deployable reflectors, the position of these reflectors and their deployment are well combined only with one-dimensional structure panels ("accordion") and bad - with their two-dimensional location (in the form of "pavers"). For reflectors, as described in U.S. patent 5520747 characteristic other disadvantage. The reflectors are formed on the side panels, where the solar cells. Accordingly, they will hinder the use of solar panels at any time (for example, transition orbit), when these panels are in the retracted position, preventing the deployment of reflectors. In addition, under the threat may be the whole process of generation of energy for KLAH if SB is I during deployment of the reflectors.

Another way of concentration using reflectors is in the distribution of small reflectors for solar panels. Reflectors alternately placed between the rows of solar cells, that allows to weaken the action of the above-mentioned disadvantages or completely eliminate them. The second characteristic of the present invention relates to such a configuration. Some of the variants of implementation, based on the geometric principle described in the documents USP 6188012 and WO 00/79593 A1.

The design described in the document USP 6188012, applies only to the deployed hub. Deployment is provided here due to the springs of several types. After deployment, the spring is used to maintain tension reflecting film. The main disadvantage of this device is mechanical fatigue taking place after a long stay in space (with heat cycle after each Eclipse). The CLA used in the field of communications, the solar panel must be in fully operational condition within 15 years in geostationary orbit. Per day is one Eclipse. Thus, the result of more than 5000 daily eclipses will be more than 5000 thermal cycles. If the tension of the reflector gradually changes due to weakening of the spring, the origin of the result of the deterioration of the optical characteristics and uniformity of illumination. There is a sharp decrease in the current ratio of concentration with a significant loss of power generation for the KLAH. For this reason, after deployment requires the use of special clamps reflective film, so that their mobility is no longer led to the weakening of the tension. In addition, in this patent proposed ill-founded principles of deployment and storage. Indeed, in the folded position, the length of the reflectors seems less than maximized. On the real drawing should be, undoubtedly, it is seen that in the folded position of the reflective film is partially obscures solar cells. In the event of a failure in the deployment of the reflector reflecting shade film solar cells, so that the generation of energy is terminated. This is another disadvantage, which shall be resolved in accordance with one of the features of the present invention.

In document WO 00/79593 A1 proposed the idea of using samorazvitiya reflectors. In the folded position they will certainly be the most obscure items. After deployment, there is no locking mechanism. During the storage of solar panels in the traditional way are arranged in a stack with small intervals between them. This available space is used for the stacked reflectors for safe d is her but because in the folded position there are no locking mechanisms, reflectors, rear i added reflectors adjacent panel (i+1).

Advantages of the described construction is quite questionable, since the vibration (e.g., during transportation and launch) can cause scratches on the reflective film, resulting in deterioration of optical characteristics, and subsequently reducing the efficiency of concentration of solar radiation with decreasing energy generation.

In paragraph 1 of the claims defined the characteristics of the solar generator in accordance with the first variant of the invention. The purpose of the invention is to create a compact and mechanically robust construction, the rigidity of which is obtained through the use of a combination of wedge-shaped reflectors and mobile mesh panel that gives a higher cooling efficiency.

Other preferred embodiments of this construction is given in the dependent claims.

When using hard reflectors (no deployment) geometric concentration appropriate to reduce to a ratio of 1.6:1, which will greatly reduce the height of the reflector (46% of the height of the reflector with a concentration of 2:1). The height of the thus obtained solar panel remains PTS is ery close to the height of the panel without concentration (without reflectors), so there is no threat of deployment and, therefore, significantly increases the reliability of the design.

Solar generator in accordance with the first variant of the invention consists of a rigid solar panel with rows of solar cells and reflectors (wedge-shaped), are alternately attached to the panel. Reflectors can be oriented at an angle of 30 degrees relative to the perpendicular to the panel to reflect solar radiation on solar cells with a concentration ratio of 2:1. The size of the reflector depends on the size of the solar cells and the concentration coefficient. When the concentration ratio of 2:1, its width will be the same as the width of the element, and the length equal to the length of one panel.

According to the second variant of the invention, the sawtooth (or wedge) reflectors made the deployed and retracted position not overlapping the rows of solar cells.

After deploying reflectors collect and concentrate the solar radiation on the solar cells. In accordance with one of the preferred embodiments, prior to deploying reflectors stacked on the substrate panel such that remained as a compact foldable design, as in traditional rigid panels without a hub.

According to the first or second the mu variant of the invention, reflectors can be made in the form of a thin film coated on top of it a layer of metal. In accordance with one of the embodiments, the film can be firmly mounted on a rigid lightweight frame and is in a state of pre-tension. According to another variant, only half of the reflector is made of film, firmly mounted on a rigid frame. According to another variant, the reflectors are made from rigid lightweight material such as a polymer reinforced with carbon fiber, or in the form of a thin Nickel plate. In accordance with another variant, the reflectors are in the form of a thin film without a rigid frame that is glued around the edges to the substrate panel or embedded in a panel design. The form of films produced by tension due to the presence of elements (deployed), glued to the panel and reaching up to ″ridge″ wedge(s) of reflector(s).

In accordance with the present invention, the reflectors replace the rows of solar cells. The weight of the solar cell type GaAs is about 0.85 kg/m². Together with a glass floor, connecting elements and cables share the same number of solar cells is approximately 1.2 kg/m². Thin-film as the reflector is much easier. For example, the film brand Kapon® thickness of 50 microns (2 mils) weighs only 71 g/m²and the plate of a Nickel alloy with a thickness of 10 microns - 89 g/m². Even with the construction details and the mechanism used to fasten in the folded position, deployment and final fixing, installation of reflectors according to the invention in no case will not lead to an increase in the weight of the solar panel. Reflective tape can be performed with the substrate not only from Kapton, and other material, so, it is a suitable replacement can provide a Mylar® or LaRC CF-1.

From the point of view of cost, solar reflectors are cheaper than solar cells of equal area, which is another advantage of the construction according to the invention.

Because of KLAH with a stabilization of the housing in the space provided for the possibility of single-axis tracking, in the plane of East-West is relatively accurate over (order ±2 degrees). In the plane of the North-South tracking is not performed. This leads to seasonal changes the orientation of the panels relative to the sun. Axis North-South changes occur in order ±23.5 degrees. For this reason, hubs are often linear with the concentration of sunlight in the direction in which the tracking. For this purpose, we offer a series of reflectors oriented OS along the North-South as a result they concentrate the solar radiation only along the axis of the tracking. When using reflectors tray-type with a geometric concentration of 2:1 and reflectors oriented at an angle of 60 degrees relative to the solar panels, the efficiency loss trapping radiation reaches 10% when the deviation of the pointing axis tracking, equal ±6.5 degrees. This never happens, unless you lost control over the position in space. Given that on the second axis, the concentration is not carried out, seasonal changes do not have any appreciable effect on the capture of solar radiation in comparison with a solar panel without concentration.

Through the use of reflectors of solar radiation, built-in panel, it is possible to obtain a more flexible modular deployable solar panels in comparison with the known systems, where the reflectors are adjacent to the panels (hubs tray-type). Indeed, in this latter case, the deployment of solar panels are easily feasible only with one-dimensional version ("accordion"). The result is a large wingspan, making it difficult alignment and adjustment. The design of the same according to the present invention is also suitable for more complex deployment configurations - type two-dimensional races is the provisions in the form of "pavers". As a consequence, significantly increases the degree of modularity in comparison with the known systems.

One of the important parameters of the solar panel is its thermal behavior. In a known hub tray-type (see, for example, figure 2) is increased solar radiation to the panel, however, there is no simple way of allotment of additional heat. The temperature of the element increases by 30-40 degrees, which leads to undesirable decrease its efficiency. This is caused mainly by the fact that although due to the use of reflectors, the surface of the capture of the stream is increased, the cooling is provided by the same area of the rear and front surfaces of the panels facing the cold outer space.

In the construction according to the invention, the reflectors are installed on the panel, and the solar radiation is still concentrated in the same amount on the rows of solar cells. However, there is no significant increase in surface capture - it remains almost the same as the surface of the panel without concentration, where the cooling surface is the same as the surface illuminated by the sun. You can expect only a slight increase in temperature. The efficiency of energy conversion are higher than when working with flume hubs is.

In the case of uniaxial tracking is usually the deviation of the order of 1-2 degrees, this will disturb the distribution of the solar radiation, which ceases to be uniform.

In panels with hubs tray-type deviation guidance leads to excessive coverage of some of the rows of elements and insufficient coverage of other ranks. Photovoltaic cells provide the transformation of light energy into electrical energy. Produced electric current is directly proportional associated with the absorbed solar radiation. Some of the items give a current of greater magnitude than the other. When such current fluctuations serial connection elements is unacceptable. If you do not provide significant improvements in terms of management of generation and collection of energy, such irregularity will lead to lower power collected from the entire panel.

The present invention is free from this drawback consisting in the violation of uniformity. Since each pair of reflectors affects a single row of elements, the deviation guidance will create uneven flow, distributed across the width of each element and the same for each of the solar cell. Impact on the transformation of energy in the element is the same in each element Yves each row of elements. The induced electric current is also the same for each of the solar cell. Eliminates the risk of deterioration of the PTO when the serial connection. No modifications are necessary in the management of the generation and collection of energy compared to the panel without concentration, and no additional loss due to pointing errors.

Reflectors show a high reflectivity, due to the use of aluminum layer obtained by vacuum deposition, or, in a more preferred embodiment, the silver coatings with additional protection. You can use other coatings are subject to obtaining a high ability to reflect sunlight. In the sensitivity range of the element, the average reflectivity of the aluminum film at an angle of incidence of 60 degrees relative to the normal to the reflector is about 89%. Silver plated, secure, optimized thin layer of SiO₂allows in the same conditions to increase the average reflectivity is up to 97%. The additional cost is easily offset by more intensive trapping solar radiation.

The proposed reflectors are kind of narrow ribbon. Its width is approximately equal to the width of the solar cell (40 mm). Such film properties as the degree Serkov the employment or the accuracy of the forms have a greater tolerance or easier to regulation, than in large reflectors used in the hub tray-type (standard width ˜2 m). In the simplified design and manufacture of film and substrate. In addition, it becomes possible to reduce the weight of the reflectors.

Below is a more detailed description of the invention with reference to the attached drawings, on which:

figure 1 is a schematic illustration of a solar generator in accordance with the first characteristic of the invention. Reflectors made in the form of saw teeth (or "tents"), arranged in rows, placed between rows of solar cells. For this option, the concentration coefficient is equal to 2:1;

figure 2 represents the image of the known device according to U.S. patent No. 5520747, 6017002 or 6050526, i.e. trough concentrator with reflectors, installed next to the solar panel. The concentration coefficient is equal to 2:1;

figa and 3B illustrate, respectively, the efficiency of capture - CE depending on the tracking error in the hub, shown in figures 1 and 2, and the light distribution on the solar panel when the deviation angles, equal to 3 degrees, figa shows the dependence of the efficiency E of the angle of incidence αthat gives efficiency curve trapping CE (where CL curve of the cosine of the angle, a CF - adjusted flow), and figv shows the dependence of normalises the spent stream NF from the normalized ordinate NO axis deviation guidance;

figure 4 illustrates the reflectivity R of the reflective film at an angle of incidence of 60 degrees relative to the normal to the reflector for unpolarized light as a function of wavelength WL. Also shown is a typical characteristic of CR mnogovershinnoe solar cell GaAs/Ge and spectrum of solar radiation SSP. For comparison given reflectivity REF aluminum layer obtained by vacuum deposition, and reflectivity PREF silver coating with additional protection (SiO₂thickness 160 nm);

figa-5E illustrate various embodiments of the construction according to the invention in the unfolded position:

5A - wedge-shaped reflector, made in the form of a thin film on a rigid lightweight aluminum frame,

5B is one half of the wedge-shaped reflector, similar to the design on figa, and the second half, made only from stretched thin films,

5C is a wedge-shaped reflector made only from a thin film, and the tension is achieved by fixed rigid elements reaching ″ridge″,

5D is a rigid panel, consisting of wedge-shaped reflectors, without the possibility of deployment. The concentration coefficient is equal here to 1.6:1,

5E - wedge-shaped reflector made in the form of inflatable structures. Deployment until the desired shape is achieved wealth is giving inflating a membrane reflector. The membrane material is deposited reflective coating;

figa-6C illustrate various embodiments of the construction according to the invention in the folded position (to start):

6A - construction according to figure 5 In a demonstration of reflectors, locked in the folded position,

6V - design according figs demonstration reflectors, locked in the folded position,

6C - design according fig.5D with two adjacent solar panels in the folded position;

figa and 7B illustrate the improved heat inside the layered cell of the honeycomb structure solar panel:

7A - thin additional cell of the honeycomb construction with exposed painted black (or with black coating) items that are installed on the back sheet of the solar panel,

7B is a view of the rear sheet with an open (cut) area under the rows of solar cells, for exhibiting cellular cellular elements directly into the cold space;

Fig illustrates the dependence of the maximum temperature (° (C) on the front page under the solar cells (T_MAXand under the reflectors (T'_MAXdepending on the average thermal conductivity of CFRP sheet (polymer reinforced with carbon fibre) with full lighting solar panel in terms of working on gestatio the ary orbit. The improvement in thermal conductivity is explained by the inclusion of the copper strands in the texture carbon fiber, or in a special "vysokoteploprovodnyh" CFRP.

Figure 1 shows a solar generator according to the invention. Here can be seen the rows of wedge-shaped reflectors 3 with two flat or curved sides 3₁and 3₂alternating with rows of solar cells 2. They are installed on the panel 1 having a cellular honeycomb structure. This cell honeycomb panel 1 made in the form of a cellular honeycomb aluminum grille, located between the two outer sheets of polymer reinforced with carbon fiber (CFRP). Wedge-shaped profile formed by the inclined sides 3₁and 3₂separated by flat areas, each of which includes one series 2 solar cells. These sloping sides applied reflective coating. Solar radiation falls on the front side of the panel. It falls on the solar cells, either directly or after reflection from the reflective coatings wedge-shaped profiles 3. In accordance with one of the preferred embodiments, the width of the number of elements is 2 equal to the width of a number of wedge-shaped reflectors 3. The angle of the sides of the reflector may be 30 degrees relative to the perpendicular to the base panel 1. In this case, the ratio of the geometric concentration with the hat 2:1. This means that two square meters of solar radiation concentrated on one square meter of solar cells. Given that high efficiency solar cells are too expensive, this concentration is very attractive from the viewpoint of cost reduction.

Inclined reflectors 3 solar radiation is made in the form of a thin film, which is applied to a reflective (e.g., metal) coating. A thin film may be made of materials such as Mylar®, Kapton®, LaRC CP-1 or any other lightweight material with sufficient mechanical strength. The film thickness depends on the required mechanical strength. Typical thickness is in the range from 13 to 125 microns and such films exist now. In accordance with one of the preferred embodiments, as the material of the reflective film used Kapton® thickness of 50 microns, which provides its own sufficient rigidity.

According to one of embodiments, there is a preformed sheet of CFRP flat surfaces, which are the rows of solar cells 2, and a wedge-shaped areas of coating in the form of a reflective layer or film forming reflectors 3.

Through the use of reflectors of solar radiation, built-in solar panel, Uday is I get more flexible modular deployable solar panels in comparison with the known systems, where reflectors are adjacent to the panels. Indeed, in this latter case, the deployment of solar panels are easily feasible only when using one-dimensional location ("accordion"). For comparison, figure 2 shows a traditional type design of the reflector with the solar panel SP and the solar cells SC, characterized by the same concentration ratio - 2:1. Its deployment is in accordance with the principle described in U.S. patent No. 5520747, 6017002 or 6050526.

The design according to the present invention is also suitable for more complex deployment configurations - type two-dimensional locations as "pavers". As a result, significantly increases the modularity of this design and it becomes possible to easily adjust the level of energy generation.

In the construction according to the invention there is no significant increase in surface capture - it remains almost the same as the surface of the solar panel without concentration. The cooling surface is the posterior surface of the panel that faces to the cold space. Because stored close values for the surface area illuminated by the sun, and the surface area of cooling, you can expect only a slight increase in temperature. The efficiency of energy conversion here to enter the, than with flume hubs. Indeed, in the known constructions, the surface trapping almost doubled, while the cooling surface remains unchanged. There is a significant increase in temperature (30-40 ° C), decreasing the efficiency of the elements, deteriorating the generation of energy.

Heat balance in the proposed design can be optimized, ensuring maximum cooling elements due to the efficient transfer of radiant heat on the back side of the panel. This is done through the use of cellular cellular structure of the solar panel 1. This cell structure is formed by the grating 4 of the cell, located between the two outer sheets 5 and 6. It is advisable to apply at the cellular elements of the black coating to increase emissivity. In this case, increases heat dissipation from the rear side of the solar panel in a cold space, and it can be enhanced further by applying additional lattice 8 cell cellular structure with open items, which is mounted just to the rear side of the panel (figa) and converted to a cold space, acting as a radiating heat exchanger. It is advisable to apply for these open items coated with a high emissivity in the infrared range of the type known p is d name Martin Black™ . In accordance with another embodiment, shown in figv, back sheet 6, made for example from CFRP, in some places charge by the formation of holes 7, through which some of the elements of the lattice 4 layered panels 4, 5, 6 are exposed directly to the cold space. It is advisable that these openings 7 and, consequently, the open items were placed under the rows of solar cells 2 and covered with a layer of high emissivity in the infrared range. Of course, if you implement this option, the design should take into account the stiffness of the panel. On figv as an example, here is an implementation option, according to which the back panel is made in the form of contour of the CFRP strips to provide the best heat exchange with a cold space and a sufficient rigidity. In addition, as is seen on fig.5D variant implementation, due to the structural rigidity of the reflector 3 can increase the rigidity of the cell of the honeycomb panel. Thus, requirements for mechanical characteristics of the panel can be met using cell cellular structure of a lesser thickness, and/or you can also prevent the removal of the back sheet 6, as shown in figv. That is true for prisverlivaem reflectors or for such resort is by the reflectors, which in the unfolded position increase the rigidity of the solar generator in the presence of the proportion of the impact of the deployment mechanism.

Possible weight reduction and intensification of cooling of solar cells due to better heat dissipation from the front to the rear cell of the honeycomb structure of the solar panel 1.

Direct impact on the design of the solar generator provides the accuracy of the orientation of KLAH. Reflectors should be designed taking into consideration the range of changing the direction of the sun's rays relative to the solar panel. On KLAH with stabilization of the body in space is not provided funds tracking axis North-South. Seasonal changes are ±23.5 degrees. For this reason, when designing the hub is not permitted concentration for this axis. Tracking the sun is along the axis of the East-West accuracy ±2 degrees. It is assumed that in order to ensure sufficient reliability of the hub must perform its functions even when somewhat more significant tracking error.

On figa and 3B illustrates the effects of pointing errors. This modeling is true for both the wedge-shaped hub of figure 1, and the tray hub of figure 2 with the ratio of the geometric concentration equal to 2:1 Axis deviation guidance corresponds to only roll KLAH on the line East-West. On figa shows the dependence of the capture efficiency E from the corner α the incidence of solar radiation. The first reason for the loss of efficiency is the law of cosine. With increasing angle of incidence decreases illuminated zone on the law of cosine. This is true for any surface that is angled relative to the direction of the sun, and is not associated with concentration. This is the main reason for the need of sun tracking for any stable KLAH.

The second factor affecting the efficiency loss associated with concentration. There is a performance drop of up to 50% when the deviation of the pointing of the solar generator relative to the sun at 30 degrees. At 60-degree deviation capture becomes zero. On FIGU shows the dependence of normalized flow NF from the normalized ordinate NO axis deviation guidance for the real case deviation of pointing only about 3 degrees. Here is given the display light distribution between the two reflectors. This zone is occupied by the solar cells. In the case, according to this invention, according to the design in figure 1, this zone is occupied by a row of solar cells. The normalized ordinate NO shown figv, corresponds to the width of each individual solar cell. For known systems (see figure 2) specified AOR is e corresponds to the width of the solar panel, including multiple adjacent solar cells. The normalized ordinate NO shown figv corresponds to the width of the solar panel. Any uneven distribution reflects on the adjacent solar cells. Some of the items will get about 65% of nominal flow NF. Impact on the transformation of energy will be provided in the same proportion. The electric current generated by these elements will constitute 65% of rated current. Series connection of elements requires a high degree of uniformity of the generated current so that you can collect power from the solar panel. Uneven light emission leads to a significant decrease in incoming order KLAH energy.

In the construction according to the invention (Fig 1) unevenness also occurs, but only on the element width. Losses in the capture of light due to deviation of the guidance are of the order of 4.5%. Approximately the same size and have loss of energy generation solar cells. For each element, characterized by the same loss rate, so that remains uniform generation of energy from element to element. Thus in each row still works perfectly sequential connection and any additional losses are not expected.

Loss Olaf the-air traffic management, taking place at the deviation guidance also depend on the concentration coefficient. At a concentration of less than 2:1 (for example, a 1.6:1 for a variant implementation, shown in fig.5D) loss demonstrate less sensitivity to the deviation guidance.

As a reflective coating for a wedge (or tent) of the reflectors used is preferably a layer of metal such as aluminum or silver or any effective coating or film capable of reflecting solar radiation. Extensive use of aluminum coatings is explained by the ease of their production and their high resistance to the effects of the space environment (mainly radiation). Since silver does not possess sufficient radiation resistance, is required to cover its additional transparent layer, in which it is advisable to use MgF₂, TiO₂and SiO₂and of these three compounds, the latter is the most inexpensive and perfectly meets the requirements imposed by the spectrum of solar radiation. Given indicated the need for additional floor, with silver work is not as easy as with aluminum. However, the reflective film with silver plated and have a certain advantage is their higher reflectivity in the visible region of the spectrum. It is known that the film obtained by vacuum deposition of aluminum, has a reflectivity 89-91%, and the reflectivity of the silver film in the visible spectrum reaches 96-98% at the fall of the radiation perpendicular to the surface. The spectral range is not limited to the visible area - multi solar cells made from GaAs/Ge demonstrate sensitivity in the range from 350 to 900 nm. The intensity of the solar radiation in this spectral region is uneven at the level of 450-500 nm maximum intensity in the UV range is the disappearance of flow, and in the red region and the infrared region there is a slightly less weakening.

In one case, the specific application of interest is the reflectance at an angle of incidence equal to not 0° (normal incidence), and 60°. Figure 4 illustrates the reflectivity R at the angle of incidence 60° (relative to the normal to the reflector) aluminum foil-R_ARand protected silver film R_ps(unpolarized light). As a protection for silver coating applied layer of SiO₂thickness of 160 nm. For clarity and simplicity of calculations shows the spectrum of the solar radiation and the response curve of the photovoltaic element (normalized using arbitrary units). Were made integral calculations for determining the ia average reflectivity of the metal films using as weighting factors of the spectrum of the solar radiation and the sensitivity of the photoelectric element. The analysis shows that the average reflectivity is 89% for Al and 97% for Ag+SiO₂. On this basis we can estimate the gain in the capture of solar energy equal to 4% for the entire solar panel. This is true both for the design according to the invention (Fig 1), and for panels of known systems (figure 2) with the same reflective coating.

There are several ways of fixing the film on the solar panel. The choice of method is determined by the deployment requirements of the reflectors, as it directly depends on the weight of the panel. Below is a detailed description of the mounting of the film, which is illustrated by drawings on figa-5E.

On figa for simplicity, it is shown (not to scale) only one wedge-shaped reflector constituting the reflective film 21, is attached to the rigid frame 22, for example, by gluing. Frame 22 provides rigidity and tension of the film 21. To obtain a sufficient flatness of the reflective film 21 is required pre-tension. As the material for the frame can be taken, for example, aluminum or Nickel. In accordance with the preferred embodiment, used aluminum as considerations of optimal thermal conditions (thermal expansion agrees well with the film material is Kapton®)and p is the cause of its small weight (density ˜ 2.7 g/cm³). The film 21 is attached to the frame 22 by means of glue. Two-component epoxy adhesive securely attaches the aluminum film. Pre-tension is created due to the temperature difference between the film 21 and the metal frame 22 in the bonding process is the temperature of the frame 22 is supported at a lower level than the temperature of the film 21. Due to thermal shrinkage leads to a minor decrease in the size of the frame 22. After hardening of the adhesive frame 22 and the film 21 regain ambient temperature, the dimensions of the frame slightly increasing, which creates the specified tension film 21 due to its elasticity.

On FIGU presents another variant implementation using the same hub, but here the rigid frame 22 are provided with only one sloping plane. The second is formed of only the reflecting film 21. In this case, the film tension is supported by the upper bracket to a rigid frame 22 and the lower bracket to the solar panel. To achieve secure attachment suitable as adhesives to use two-component epoxy resin. The reflectors are fixed in the normal open position (under the estimated angle). In the case of deployable concentrator reflecting film can be folded in a compact position under the hard part.

In the third embodiment shown in figs, the tension of the reflective film 31 is supported within corresponding desired flatness, using a special rigid elements 30 (deployable/telescopic elements), for example, as described in document US 5244508, however, in the fully extended the straightened position. The edges of the reflective film bonded to the solar panel. Light rigid elements or curved arcs provide the necessary pre-tension in the middle of the width of the film. After deployment, the described mechanism is fixed to maintain tension reflecting film for a long service life (without weakening). Folded configuration, corresponding to the variant shown in figv. The film is put on the solar panel, pre-folded it. Special locking mechanism (not shown) prevents the sliding of the film solar cells, so that failure of the deployment is not happening shading of the latter. When the necessity is the deployment of the locking mechanism is released, and hard items (or curved arc) fully expanded in the vertical position, preferably in conjunction with the operation of the deployment of the solar panel.

Fig.5D illustrates an implementation option using a rigid wedge-shaped reflectors 3, for which deployment option is not provided. Hard reflector 3 are usually performed from CFRP, which is the preferred material for the honeycomb mesh front sheet of the solar panel. The typical thickness of the reflector of the CFRP-100 microns, although it is possible to envisage any other in the range from 50 to 200 microns. This reflector is extremely lightweight and has a large rigidity. Wedge-shaped reflectors may be affixed reflective film made from a material such as Kapton® thickness 25 microns. This variant is characterized by high rigidity, good material compatibility and high reliability (due to the lack of deployment). The weight of the reflectors here are a few more than in the previously described constructions, however, given the absence of the deployment mechanism and the locking device, the total weight remains quite satisfactory. It can easily be less than the equivalent weight of a number of solar cells.

In the shown five new variant implementation of the invention uses an inflatable structure 40, provides the General deployment of obtaining while inflating the desired configuration of the reflector. There is the possibility of optimizing the shape of the reflector for more uniform coverage in case of minor deviations guidance.

The sides of the reflector 3₁and 3₂can be flat or curved. Shape optimization affects the uniformity of illumination and efficiency of concentration in case of minor deviations guidance (often fails to track the sun about 2 degrees). When using hard reflectors exact shape't get any easier than working with deployable reflectors.

Because when embedding hard reflectors thickness of the solar panel increases, in the preferred embodiment shown in fig.5D, the concentration of solar radiation is equal to 2:1, as for the above options, and 1.6:1. Due to this reduction of concentration, it becomes possible to reduce the aspect ratios. If the width of the rows of solar cells, equal to 40 mm, the height of the reflector is reduced to 41% of this width (16.4 mm). To obtain the concentration ratio of 2:1, it was equal to 87% (34,7 mm). The angle at which the reflector is also consistent with this geometry (36.3 degrees instead of 30 degrees relative to the perpendicular to the solar panel).

When working without a hub, the total thickness of the solar panel are equal, as a rule, 20 mm In accordance with the tvii same with this embodiment (fig.5D), the total thickness is increased to 36 mm

When the solar panels are in the folded position, the panel i is combined with the next panel (i+1) to form between them a free space equal to typically 10-15 mm, the Total thickness of two stacked panels is, for example, 50 mm (=20+10+20 mm) for the case with an expandable or inflatable reflectors (type reflectors 40, shown in fige). Provided by the use of special shock-absorbing gaskets (not shown) to maintain the specified free space in a severe vibration loads (e.g., at startup). This prevents collisions between the folded panels, which could cause damage to the solar cells.

There is a possibility to change the configuration in the folded position with regard to increasing the thickness of the solar panel using mostly hard (prisverlivaem) reflectors. On figs shown folded configuration using two pivotally United (pas) stacked one on another mesh panels SP1 and SP2 with the corresponding alternating reflectors 3. Given this alternating arrangement of the reflectors, the total thickness is increased only by a small amount. If for security reasons between the upper reflector and the adjacent solar panel Bud is t be maintained free space of 5 mm, the total thickness of two stacked panels will be, for example, 61 mm (=20+16+5+20 mm). For two stacked panels is required to increase the thickness of only 11 mm (22%).

Moreover, the reflectors 3 are also as a reinforcing details solar panel. Provided appropriate modernization of the structural design of the panel (for example, reducing the thickness of the cell of the honeycomb structure) of the total thickness of the folded panels may remain even closer to the original version (without hubs). For example, when reducing the thickness of the cell of the honeycomb structure is from 20 to 18 mm, the total thickness of two stacked panels hub on figs becomes equal to 57 mm (=18+16+5+18 mm). In this case, the two folded panels is required to increase the thickness of only 7 mm (14%).

In this configuration, the reflectors will provide more efficient cooling elements. When reducing the thickness of the cell of the honeycomb structure increases thermal conductivity between the rear and front sides of the solar panel. Due to the lower temperature of solar cells they will ensure more efficient photovoltaic conversion.

One important aspect of the present invention is to achieve thermal balance. It is possible to further increase cooling efficiency due to the aligning ability to compensate middle is the temperature on the front side of the solar panel, that is, the side that is facing the sun. As the temperature of the element is higher than the temperature of the panel behind the rows of reflectors, you can use CFRP with high thermal conductivity for the front of the sheet 5 and/or the back sheet 6. Thermal conductivity standard CFRP is in the area of about 35 W/m·For, while vysokoteploprovodnyh CFRP she can reach 370-700 W/m·and they demonstrate a much higher stiffness - 490-560 HPa compared to 93 GPA for conventional CFRP. Therefore, this material is also preferred if you need a higher overall stiffness of the panel. Thus also possible to increase the transverse conductivity of the front surface of the solar panel. You can simply add to the sheet of conventional CFRP layer vysokoteploprovodnyh CFRP, which will increase the conductivity, and in addition, it is attractive from the viewpoint of the compatibility of their coefficients of thermal expansion. Another way may be to add a thread with high thermal conductivity inside or on top of a conventional CFRP, oriented on average perpendicular to the longitudinal axis of the rows of solar cells, resulting in a kind of thermal bridges between the warmer area under the elements and more cold area under the reflectors. Such threads mo is but either add in CFRP in the manufacturing process, or later. As an example, you can specify that by adding strands of copper or other conductive material on the front side of the solar panel you can increase the efficiency of solar cells, as shown in Fig where the graphs of the maximum temperatures of the front sheet under the items and under the reflectors, is calculated as a function of the total thermal conductivity of the front sheet. This improvement, albeit small, can be achieved without any appreciable increase in weight. For example, as seen in Fig, using vysokoteploprovodnyh CFRP can reduce the temperature of the elements more than 5°.

In the folded position the elements of the reflectors are stacked on each other on the surface of the solar panel. Provides for the storage of reflectors above the solar cells, in order to ensure the possibility of generation of energy in the early stages after triggering or in the event of a failure of the deployment. Thus with this invention solves one of the problems existing in the known structures.

In accordance with a second embodiment of the invention, characterized deployable reflectors, prevents shading of solar cells (see figa). Requires the use of special locking mechanism (not shown) to prevent even malaise what about the weakening of the springs, what is characteristic of the known systems. The weight of the film can be very small (as a rule, 71 g/m²for a thickness of 50 microns). In the variant shown in figa the most difficult parts are the rigid frame 22 and the mechanical parts required for fixing in the folded position, deployment and final lock. Thanks to the use of only one frame 22 (pigv) and very simple deployment mechanism cannot receive less weight for this second option. The deployment mechanism can be a spring without fixation in the folded position, as already described in the known construction (WO 00/79593 A1). However, in accordance with the preferred embodiment, it added locking device. Here, the reflectors are not amarasiriwardena, they require external power (preferably associated with the deployment mechanism of the solar panel), which would unlock and start the deployment. The reliability of such a mechanism can be very high, especially when his work is tied to the deployment cycle panel. The additional weight is very small, since they use materials with low density, suitable for operation in a space environment, the type of aluminum. The main advantage in comparison to known systems, the mi is when the solar panel is in the folded position, the reflectors do not touch each other, which prevents the occurrence of scratches on the reflective surface.

1. Solar generator with concentration, containing rows of solar cells, alternating with wedge-shaped reflectors located along these rows, characterized in that it contains at least one panel (1)having a cellular honeycomb structure containing the front face sheet (5), which has the reflectors (3) and the specified series of solar cells (2), the rear face of the sheet (6) and located between cellular mesh grating (4), the reflector (3) are deployed and in the folded position not overlapping the rows of solar cells (2).

2. Solar generator according to claim 1, characterized in that the cellular elements of the specified mesh grille (4) have a black finish.

3. Solar generator according to claim 1 or 2, characterized in that at least part of the surface of the specified panel (1) with the cellular structure of the cellular elements are open on the specified rear face of the sheet.

4. Solar generator according to claim 3, characterized in that the rear face of the sheet (6) has openings (7) and these open items cellular elements (4) are located in these holes (7).

5. Solar generator according to claim 3, characterized in that specified the haunted hole (7) at least partially located under the rows of solar cells (2).

6. Solar generator according to claim 5, characterized in that at least one of the honeycomb lattice (4) made of aluminum.

7. Solar generator according to claim 6, characterized in that at least one face sheet (5, 6) made of a polymer reinforced with carbon fiber.

8. Solar generator according to claim 7, characterized in that it contains a preformed sheet having a flat area on which to set the specified series of solar cells (2), alternating with wedge-shaped areas covered with a reflective layer, with the formation of wedge-shaped reflectors (3).

9. Solar generator according to claim 8, characterized in that the preformed sheet made of a polymer reinforced with carbon fiber.

10. Solar generator according to claim 9, characterized in that the wedge-shaped reflectors (3) is covered with a metal, preferably silver with an additional transparent layer that provides protection from radiation.

11. Solar generator according to claim 10, characterized in that the preformed sheet and/or at least one face sheet (5, 6) made of a polymer reinforced with carbon fibre, which has a thermal conductivity of not less than 370 W/m·K.

12. Solar generator according to claim 11, characterized in that the concentration coefficient is in the range from 1.4/1 to 2/1 and composition is employed, preferably 1,6/1.

13. Solar generator according to item 12, wherein at least some of the reflectors (3) represent the film, reinforced frame, at least one of its sides.

14. Solar generator with concentration, containing rows of solar cells, alternating with wedge-shaped reflectors located along these rows, characterized in that it contains at least one panel (1)having a cellular honeycomb structure containing the front face sheet (5), which has the reflectors (3) and the specified series of solar cells (2), the rear face of the sheet (6) and located between cellular mesh grating (4), the generator also contains additional bars (8) of the cellular honeycomb structure attached to the back the front sheet (6).

15. Solar generator with concentration, containing rows of solar cells, alternating with wedge-shaped reflectors located along these rows, characterized in that it contains at least one panel (1)having a cellular honeycomb structure containing the front face sheet (5), which has the reflectors (3) and the specified series of solar cells (2), the rear face of the sheet (6) and located between cellular mesh grating (4), at least one of the front leaf is (5, 6) made of a polymer containing filaments with a high thermal conductivity, oriented on average perpendicular to the longitudinal axis of the rows of solar cells (2).

16. Solar generator with concentration, containing rows of solar cells, alternating with wedge-shaped reflectors located along these rows, characterized in that it contains at least one panel (1)having a cellular honeycomb structure containing the front face sheet (5), which has the reflectors (3) and the specified series of solar cells (2), the rear face of the sheet (6) and located between cellular mesh grating (4), the generator also includes at least two pivotally United wire mesh panel (SP1, SP2)having a folded configuration such that the reflectors (3) the first and second panels are alternated.

17. Solar generator according to item 16, characterized in that the reflectors (3) are prisverlivaem.