DE102011053616A1 - Method for monitoring critical temperature trends of solar energy system installed in building, involves evaluating signals based on evaluation pattern delivered by temperature sensors at specific time - Google Patents

Abstract

The method involves analyzing module arrangement based on installation environment including assembly parameters such as assembly location, size, geometry, self-structure, topography and orientation. The points over temperature trends at reliable statement in presence of critical state are selected. The points close to photovoltaic modules (12-1) are provided with temperature sensor (28). The signals are evaluated based on evaluation pattern delivered by temperature sensors at specific time. Independent claims are included for the following: (1) a monitoring device; and (2) a function module.

Description

The invention relates to a method for monitoring critical temperature developments in solar systems and to an apparatus for carrying out this method.

Solar systems with photovoltaic modules are increasingly used in a variety of design, size and configuration. In addition to so-called solar parks, in which a large number of photovoltaic modules are put together in one area, solar systems are increasingly installed on buildings, such as on rooftops or other facade parts. The photovoltaic modules are usually in groups, d. H. Connected in series via so-called "strings", so that the electrical DC voltage provided can be fed via an inverter into a public power grid.

The electrical voltage levels provided by such solar systems can be considerable, so care must be taken that, in the event of damage or incidents, such as the occurrence of a fire, the firefighting personnel are protected against electric shock. This problem was detected early and it is for example in the document DE 20 2006 007 613 U1 described a fire protection for a photovoltaic solar system, with which it is possible in a fire to prevent a threat to fire fighters by the fact that a thermal fuse is installed in the electrical connection line between a photovoltaic element and the transfer point of the electrical voltage in the public network which provides a break in line connection at a temperature typically encountered in fires. The range of services of this fire protection is however relatively limited.

From the document DE 10 2005 018 173 B4 It is known to switch a photovoltaic system on buildings by means of a protective device in a safe operating point when a smoke, water or gas sensor emits a corresponding signal. The protective device can short-circuit the generator field or switch it to an "idle" operating point. However, the reliability of this known switching device is limited because it depends on how smart the smoke, water or gas sensors are positioned.

Various devices for monitoring solar modules have also been proposed, for example in the documents WO 2010/031394 A1 . WO 2009/026602 A1 . WO 2007/041693 A2 . EP 2 136 411 A1 . EP 1 587 148 A1 or DE 10 2008 008 504 A1 , However, these systems have in common that they remain limited to the pure anti-theft function.

In the document DE 10 2008 003 272 A1 Finally, a monitoring unit for photovoltaic modules is described, which manages to individually monitor each individual photovoltaic module for the presence or absence of a variety of functions centrally. For this purpose, in the junction box of each photovoltaic module additionally arranged a board on which a plurality of function monitoring modules is arranged, such as a motion sensor, a temperature sensor, a WLAN module, a voltage and current measurement, a power supply unit of the board or a Component for the configuration of the junction box.

However, this known monitoring unit has the disadvantage that on the one hand the retrofitting of already installed photovoltaic solar systems is enormously complex, and that the retrofitting of the photovoltaic modules remains limited to the function monitoring.

The invention is therefore based on the object to provide a method for monitoring critical temperature developments of solar systems with photovoltaic modules and a corresponding device, with which it is possible to improve the monitoring reliability with the least possible hardware outlay and for a reliable Shutdown of the solar system to use.

This object is achieved, on the one hand, by the method of claim 1 and, on the other hand, by the device according to claim 13.

According to the present invention, the respectively present installation parameters of the solar system form the starting point for the method or for the design of the device. Depending on the installation site, the size of the solar system, the geometry of the system and / or the photovoltaic modules, the intrinsic structure, the topography and the orientation of the individual photovoltaic modules or the solar system itself, meaningful points are selected first, on the temperature developments of a reliable statement can be made about the presence of a critical condition in the area of the plant. Parameters that influence the selection of these points are, for example, the building geometry, the roof geometry (roof pitch, material quality of the roof, such as brick or tin roof), arrangement of openings or open spaces, such as skylights, fireplaces or ventilation shafts, the facade geometry, other flow parameters that are caused by external influences or by the topography, such as wind directions, wind speeds or induced by neighboring buildings currents. Only those modules or coupling points between those modules that are close to these points, according to the invention equipped with temperature sensors, the signals emitted by these temperature sensors over time signals are then evaluated on the basis of a Auswertemusters which is tailored to the overall system. This gives the monitoring method according to the invention an additional intelligence, which makes it possible to differentiate much more reliably than known systems between harmless punctual temperature developments at individual positions of the solar system and the development of a dangerous situation. As a result, it is possible at the same time to classify a critical temperature development earlier than previously, because the tailored evaluation pattern evaluates the signals indicated by the temperature sensors over time, so that developments in critical situations can be detected at an early stage. According to the invention, therefore, the temperature distribution in the solar system and its development is included in the method for monitoring, which makes it more reliable than previously possible to make a statement about the actual safety status of the system.

The mode according to which the evaluation pattern is processed does not have to remain unchanged in the entire operating spectrum of the monitoring method. It is advantageous to configure the evaluation mode so that it can be up to a certain state point of the system, for example up to the time at which at least one temperature sensor reaches a signal threshold, at a simple level, such as on a event-driven level remains. Only then does the evaluation pattern apply to an evaluation mode in which the temporal development of the signals of the temperature sensors is evaluated individually and / or to one another. In this way, the signal flow can be minimized without having to accept significant functional impairments of the process.

Another particular advantage of the method according to the invention arises when the signals of the temperature sensors are processed centrally and preferably stored with a time stamp. In this way, the method can be used with little extra effort to document the emergence of a critical thermal situation, such as a fire.

With the development of claim 5, it is possible to use the inventive method simultaneously for an anti-theft device. In other words, the method according to the invention can be used very flexibly, by being used either for a fire alarm system or for theft protection of photovoltaic modules or as a combination of both.

When the DC power grid, i. H. the DC string network of photovoltaic modules is used as part of the data communication network, the cost of retrofitting already in operation photovoltaic solar systems can be further reduced.

With the further development of claim 7, the method according to the invention becomes a method with which the photovoltaic solar system can be converted into a safe state when critical thermal loads occur, for example during a fire.

With the development of claim 8, the safety of the solar system is further increased. In addition to an electronic shutdown by separation of the individual "strings" can be done in this way a targeted short-circuiting or connecting the modules to ground, which even large photovoltaic solar systems can be treated easily in the event of fire with any extinguishing agents and without risk to firefighters.

The shorting of the "strings" at selected positions is advantageously carried out according to claim 9 at the points which are equipped according to the invention with the temperature sensors. A particularly simple realization of the idea results when the temperature sensors are each integrated in a functional module via which the selected "string" of the solar system is then short-circuited in accordance with a control signal coming from a control center. It is of further advantage if the short-circuiting of the "strings" under certain conditions and, for example, when a control signal from the control center no longer reaches the functional module, is self-sufficient.

If the solar system is disconnected from the grid before disconnecting at least one selected "string", preferably on the AC side, the thermal load on the components required for short-circuiting is significantly reduced, thereby further reducing the device complexity required to implement the method according to the invention.

The development of the method according to claim 12, the prediction accuracy of the method can be further improved. The localization of a source of fire made possible by the method according to the invention can be further refined by this development.

An advantageous device with which the above-described method for monitoring critical temperature developments of solar systems can be carried out is subject matter of claims 13 to 29. The device according to claim 13 as well as the method according to claim 1 capable of critical thermal developments of photovoltaics -Solaranlage with hitherto unachieved intelligence and early to detect and - to document in an advantageous development according to claim 14, wherein the structure is made such that a minimum of hardware is needed. In this way, the device can be mounted as a low-cost retrofit kit to already installed photovoltaic solar systems. The fact that the temperature sensors are mounted only at very selectively selected points to which the evaluation pattern is tailored, the conversion effort is minimized and it is still possible to provide a monitoring of the temperature distribution and development of photovoltaic solar systems. By incorporating the monitoring of temperature distribution and evolution into the evaluation and documentation, the monitoring will not only be more accurate, but it will also be faster in time as it will allow early response to emerging hazards.

Advantageously - according to claim 15 - the analysis and control unit equipped with an evaluation logic that is freely programmable, so that a simple adaptation of the device to a variety of configurations auszustattender photovoltaic solar systems is possible. Advantageously, the DC power supply network (DC string network) of the photovoltaic modules is also used for the data communication network. For this purpose, it is advantageous to transmit the measurement and control signals modulated via the DC cabling of the photovoltaic modules.

If the DC power supply network (DC string network) of the photovoltaic modules is used as part of the data communication network (claim 17), the device is automatically equipped with an anti-theft function. In this case, it is advantageous to integrate a separate, so-called anti-theft module in the system, which is specially designed for processing the evaluation routines for the theft-protection function.

With the development of claims 18 to 24, the monitoring device according to the invention becomes a particularly effective fire protection. The fact that the temperature sensors are each integrated in a function module, this module can be designed so that it brings the potential of the "strings" in which it is located reliably to the ground potential. Although such a function module is more expensive in terms of device technology than, for example, a circuit board as used in the prior art. Due to the fact that these functional modules, however, according to the invention only have to be provided at a very selectively selected, few points within the solar system, the device complexity can still be kept smaller than hitherto usual.

Preferably, each functional module is assigned an individual, preferably adjustable temperature threshold, at which the device passes from an event control to a control according to the "polling" principle, in which the status of the functional modules and / or the signals of the temperature sensors is detected by means of cyclic queries. This makes it possible to minimize the signal flow in the device.

If the functional module is integrated in the connecting line of two adjacent photovoltaic modules, in which case preferably the plug-in connection of adjacent photovoltaic modules is used, it becomes particularly easy to retrofit existing photovoltaic solar systems with the device according to the invention.

The functional module advantageously receives a housing adapted to the relevant ambient conditions, such as, for example, a metal housing, in which preferably the entire functional components of the module are fully encapsulated. Such a functional module is able to short-circuit the respective "string" in a critical state of the solar system. In order to keep the occurring thermal loads as low as possible, it is of particular advantage if the device is additionally equipped with a power-shedding module according to claim 23, which ensures that before shorting the respective "strings" the Solar system in the AC sector is taken off the grid.

A particularly advantageous embodiment of the device is the subject of claim 27, by which it is possible to implement an event logging of the system and a telecommunications monitoring control of the system.

The development of claim 29 simplifies the device in addition, because there is no separate external power supply for the individual components required. By means of the additional electrical energy storage device, the device remains fully functional even when the supply voltage of the solar system, such as at night, falls.

Subject of a separate invention for which self-protection is claimed is a functional module according to claim 31 or 32. The fact that the temperature sensor is mounted on the mounting bracket inside the housing, results in a particularly high dynamics in the temperature measurement, because In this way, the temperature sensor is in direct contact with the aluminum substructure on which the photovoltaic modules are laid.

Advantageous developments are the subject of the remaining dependent claims.

The invention will be explained in more detail with reference to schematic representations. Show it:

1 a schematic side view of a building, on the roof construction, a photovoltaic solar system is installed, which is equipped with a device according to the invention for monitoring critical temperature developments;

2 the side view of the building 1 with implied environmental development;

3 in an enlarged view a side view of the roof construction with mounted solar system to illustrate the environmental influences on the assembly of the solar system with the components according to the invention;

4 a schematic partial view of photovoltaic modules of a "strings";

5 the view of 4 from underneath;

6 a schematic functional representation of a functional module used in the inventive device;

7 a schematic representation to illustrate the operation of the breaker and modulator-demodulator component in the function module according to 6 ;

8th a schematic representation to illustrate the total interconnection of the device according to the invention; and

9 a schematic representation of the structure of the detail according to "IX" in 8th ,

The 1 and 2 show views of a building that is equipped with a solar system with photovoltaic modules. The solar system can be constructed arbitrarily, for example, have photovoltaic modules of different types. These are in 1 with the reference numerals 12-1 respectively. 12-2 designated. The individual photovoltaic modules 12-1 and 12-2 can be done in a variety of ways via their respective electrical connection lines 14 be summarized into so-called "strings".

In general, such solar systems on a support structure (in 1 not shown in detail), which are usually mounted on the roof structure mounting rails, such as aluminum rails 24 (please refer 3 ) is formed. With the reference numerals 16 windows or roof windows are designated and with the reference numeral 18 a fireplace that protrudes from the roof construction.

The side view of the building according to 1 indicates that the solar system follows the roof pitch in this embodiment shown. However, it should be emphasized at this point that the invention can of course also be used in conjunction with solar systems that are mounted in any spatial arrangement, for example in solar parks or on flat roofs.

With the additional equipment of photovoltaic solar systems to be described in more detail below, a system is to be created which, while minimizing the technical complexity, succeeds in monitoring the photovoltaic solar system itself as well as the surroundings adjacent to the solar system with regard to inadmissible temperature developments and with the greatest possible safety to operate.

The invention is based on the consideration that the individually present installation parameters of the solar system are of decisive importance for the validity of one or more state measurements in the area of a photovoltaic solar system. For this reason, according to the invention, the solar installation is analyzed with regard to its installation environment, taking into account the respective assembly parameters in each case, whereupon a selection of meaningful points X (FIG. 1 ), the temperature development of which a reliable statement about the presence of a critical condition in the area of the plant can be made.

As a mounting parameter, for example, the mounting location and / or the size of the solar system and / or the geometry of the system and / or the intrinsic structure of the system, ie the shape and spacing of the individual photovoltaic modules to each other, and / or the topography of the solar system and / or the orientation of the solar system used in the room. In the selection of the meaningful points X, over the temperature developments of which a reliable statement about the presence of a critical state in the area of the plant can be made, is therefore in addition to the geometry of Solar system also included the environment. For the embodiment shown, this means that when selecting the points X whose temperature development is to be monitored, the roof pitch, the material properties of the roof (tile roof, sheet metal roof, other materials and composite material), the position of the openings, ie the roof window 16 and the fireplace, the facade geometry of the house and its openings, such as the windows 16 or the presence of stems such as a terrace or the like, the electromechanical structure of the photovoltaic solar system and the overall topography, ie the integration of the solar system in the neighborhood, ie the location of the solar system in relation to adjacent buildings 20 . 22 , be taken into account. Thus, the decisive external influences, taking into account the fluid mechanics aspects including the meteorological wind direction and wind speed and the building-technically induced currents, such as those in the vicinity of high-rise buildings 22 be included in the selection of meaningful or neuralgic points X.

It becomes thereby for example - as in 3 indicated schematically - takes into account that the photovoltaic modules 12-1 respectively. 12-2 over a substructure 24 on the roof surface 26 , ie are mounted at a distance A, so that - as indicated by the arrow TKL - cold air is sucked in at the lower end of the solar system, so that this colder air one of the roof surface 26 following thermals TKL generated.

With the arrow HL in 3 is indicated that in the case of a fire occurring in the building, a state is established in which hot air exits at the highest point. The case RT indicates that in the area of the roof in case of fire, a certain smoke thermals results, with the interaction of the hot air flow and the smoke thermals results in a state in which - as indicated by the arrow KL - sucked cold air becomes. Taking into account the in 2 schematically indicated meteorological wind direction WR and resulting from the integration of the building into the environment building thermals - as indicated by the arrows GT1, GT2 and GT3 - thus points X can be found on their individual temperature development and / or on their temperature development To each other a particularly reliable statement can be made about whether there is a critical thermal state in the area of the solar system, which threatens either the solar system or the building, for example, when breaking out of a fire.

The criteria according to which the decisive points X are selected for this prediction also determine the evaluation pattern to be described in more detail below, preferably as individually compiled software, according to which the temperature development at these selected points is evaluated.

Those photovoltaic modules which come closest to the meaningful points X described above in accordance with the invention are provided with temperature sensors 28 equipped, preferably in a functional module 30 are integrated. The following is based on the 4 to 7 described how the function modules 30 preferably constructed and integrated into the apparatus for monitoring critical temperature developments.

From the 4 and 5 shows that the function modules each on a mounting rail 24 mounted and - preferably via a plug connection - in the DC network or the DC string network 32 the photovoltaic modules 12-1 respectively. 12-2 are integrated.

As is clear from the 5 results, the integration of the function module takes place 30 in the photovoltaic system such that the DC power connection line between two photovoltaic modules 12-1 respectively. 12-2 is preferably separated at a connector and that at this point the function module is incorporated. The structure of the function module goes in detail from the 6 and 7 out.

That with 34 designated and schematically illustrated housing has a mounting or mounting tab 36 , with a preferably thermally good conductive connection with the relevant mounting rail 24 can be done. The mounting tab 36 , which preferably consists of a thermally highly conductive material, carries a temperature sensor or sensor 28 preferably within the housing 34 lies. This has the temperature sensor 28 a direct contact to the mounting bracket 36 , which is made of aluminum, for example, and thus to the substructure or to the relevant mounting rail 24 , which succeeds, which is usually made of metal such. B. aluminum formed substructure forwarded heat metrologically well and quickly detect. Due to the mounting of the temperature sensor inside the housing 34 results in a high dynamics in the temperature measurement. Finally, the housing can be used to adapt the function module to the ambient conditions. For this purpose, it may be beneficial to the housing 34 designed as a metal housing and to shed the components housed inside.

On both sides of the case 34 is a plug 38 intended for connection to the DC-String network.

The integration of the functional module 30 in the monitoring system is such that the DC string network 32 is used for data communication. For this purpose, a microcontroller (μC) 40 provided the data communication via a modulator / demodulator 42 controls, makes the temperature measurement and can make an electronic string separation upon receipt of a corresponding control command. For this purpose is a breaker 44 provided, on the one hand serves to open if necessary, an electrical switching or relay contact to interrupt the string, and on the other hand can act as a mechanical NC, which triggers at too high a temperature. In this regard, he may for example be designed as a bimetal switch, which can provide additional security in case of failure of the electronics.

With the reference number 46 is a power supply indicated, which is the electrical energy from the connected DC cables 32 to supply the functional module 30 In addition, the power supply is advantageously used to supply all functional blocks of the module with electrical energy suitable voltage levels, on the one hand from the connected DC voltage and on the other from a further, integrated electrical energy storage 48 , which is formed for example by a Li-ion battery. The power supply 46 serves in this case at the same time to store electrical energy in this electrical energy storage or battery, so that the function module 30 also remains functional at night.

In order to use the DC-String network for data communication, the modulator / demodulator 42 to the breaker 44 connected in parallel, via a pair of signal coupling elements. The modulator / demodulator 42 converts those from the microcontroller 40 incoming data into a modulated signal or translates the incoming modulated signals into a corresponding control signal for the microcontroller. The modulated signal is transmitted via the signal coupling elements 50 transferred to the existing DC cables of the photovoltaic system by the electrical functional unit of the coupling elements 50 the modulation signals on the DC voltage lines 32 coupled and uncoupled. Each function module receives an identification number (ID) with which it can be uniquely identified in the overall network.

The overall interconnection of the monitoring system is in 8th shown schematically. Accordingly, the DC lines or the individual DC strings 32-1 to 32-n with the integrated function modules 30 on a string coupling module 52 connected via a data bus 54 , which is used simultaneously for the power supply, with an analysis and control unit 56 connected is. Via another data bus 58 is the analysis and control unit 56 with a receiving and transmitting module 60 connected, which provides the data communication interfaces, and preferably a data read-out device.

With the reference number 62 is a module for emergency shutdown of the system and with the reference numeral 64 A network drop module called behind an inverter 66 in AC network (AC network) 68 located.

Details of the structure of the modules 52 and 56 arise from the 9 , One recognizes that one with 66 designated housing of the string coupling module 52 a power supply 68 , a modulator / demodulator 70 and an electrical energy storage 72 recording, even at night autonomous operation of the string coupling module 52 guaranteed. About the modulator / demodulator 70 the signals coming from the analysis and control unit are coupled into the data communication system or decoupled from this.

That with 74 designated housing the analysis and control unit 56 takes a microcontroller 76 and a control 78 on. Preferably, the string coupling module 52 over plug 80 into the DC network or into the individual DC strings 32 built-in.

The individual functions of the individual components of the monitoring system are explained in more detail below:
The function of the function modules 30 consists mainly in the temperature at the mounting location, ie in the embodiment shown on the roof below the photovoltaic modules 12-1 respectively. 12-2 nationwide and to measure in certain, predetermined intervals and to generate an alarm signal when exceeding an individually predetermined, preferably freely programmable signal threshold, which may be different for the different positions, which together with the identification number (ID) on the string coupling module 52 to the analysis and control unit 56 is sent. In the analysis and control unit 56 the measurement result is stored, preferably with a time stamp.

Once the first measurement result has been stored, the evaluation pattern of the analysis and control unit goes into a mode in which the temporal evolution of the signals of the Temperature sensors individually and / or evaluated in relation to each other. Since the individual measurements are made and stored at predetermined time intervals or with fixed time intervals for each point, a complete documentation of a fire development can be provided with the monitoring system according to the invention, wherein the reception and transmission module 60 at any time the reading of the temperature data is possible.

In order to keep the data flow within the monitoring system as small as possible, it is advantageous to carry out the temperature recording by means of a so-called location temperature difference measuring system, which operates as follows. The first received ID address with the highest measurement result receives no further input in the analysis and control unit for the further measurement cycles 56 , Instead, the remaining function modules are used to measure the difference 30 or the temperature sensors located there interrogated, in which way it is determined which measurement is equal to the next higher measurement result. This measurement result is again stored and stored in a second rank, whereupon the relevant ID address of the associated function module is locked again. In this way, all location-temperature difference measurements are software-controlled and run in a fixed schedule with a minimum data volume.

When the temperature development at the individual function modules 30 Compared with the evaluation pattern tailored to the system, it can be concluded that a sufficiently reliable statement can be made about the existence of a critical temperature development in the area of the installation. This is done with the analysis and control unit 56 an alarm signal is displayed and over the data bus 58 to the receiving and transmitting module 60 given, which sends a corresponding message, preferably stating the location and extent of a fire, to a fire alarm panel. At the same time it can be provided that this message is also transmitted to the operator of the system. The transmission can be wireless, for example via GSM radio, but also by wire, for example via an ISDN line.

Simultaneously with the notification of the alarm or fire situation to the fire panel, the receiving and transmitting module sends 60 or the analysis and control unit 56 a corresponding data packet to the network drop module 64 over which the AC network is dropped. Subsequently, at least selected function modules 30 instructed via an associated control data packet to separate the respective DC string and short circuit. The electronic shutdown takes place via an electronically controllable switch, preferably via a thyristor, and is preferably constructed so that the complete system also for maintenance via the analysis and control unit 56 switched off and controlled can be switched on again. Of course, it should be taken into account that the components are designed so that the occurring currents, which can easily be far more than 20 amps DC, cope, in addition, it must be ensured that the electrical energy storage 48 in the functional module 30 is designed so that it still provides enough power for the electronic shutdown even after several hours of power failure through the DC string network.

At the same time is the function module 30 equipped with a mechanical DC power brake. This is preferably at the attachment tab, ie where the temperature measurement takes place. This mounting point is the direct main indicator of a thermal transfer to a bimetallic DC protector, which serves in a thermo-technical problem, such. B. at a melting of the functional module 30 to separate the DC string. The temperature resistance of this component should therefore be at least 1000 ° C, and it is advantageous to work in this area with ceramic components. The short-circuit current flowing during the emergency shutdown is also transmitted via the fastening strap 36 led, as these as electrical Ableiterpol to the earth, ie to the mounting rails 24 leads the photovoltaic solar system and provides a large cable cross-section for deriving the DC short-circuit currents.

As already mentioned above, the monitoring points, ie the positions of the functional modules are determined individually according to the module arrangement with respect to the installation environment, taking into account the present installation parameters. Therefore, it is also beneficial if the individual function modules 30 individually programmable or adjustable, so that they can be used for a wide variety of solar systems. In this way, for example, each function module 30 be assigned a different temperature signal threshold, when exceeded, a first alarm signal is emitted.

During commissioning, an ID address assignment and assignment to the individual function modules takes place first 30 as well as the recording of the ID addresses to the analysis and control unit 56 , By means of a suitable startup software, the individual function modules report to the analysis and control unit 56 that with a corresponding Acknowledgment command responds, whereupon all modules are released.

The operation of the control is such that a mixture between a so-called event control and a control according to the so-called "polling" principle takes place. Extraordinary events at the function modules 30 be immediately to the analysis and control unit 56 reported, such as B. a strong change in temperature in a short time or exceeding the associated signal threshold of the respective functional module. For this purpose, the analysis and control unit demands 56 Constantly and in fixed cycles data from the individual function modules 30 at.

At the latest when at least one functional module 30 an extraordinary event, so z. B. signaled reaching the individually adjustable temperature threshold, all function modules 30 queried by the analysis and control unit in a fixed time cycle. The system accordingly proceeds from an event-controlled mode of operation into an operating mode in which the analysis and control unit controls the individual function modules 30 polls cyclically (polling). In this way, a temperature profile with a time course similar to a movie recording can be created, and the analysis and control unit can evaluate the temperature development with the help of individually tailored software depending on the individually present assembly and environmental parameters.

Due to the preferably free programmability of the individual functional modules on the one hand and the analysis and control unit on the other hand, the monitoring system according to the invention can be adapted to all conceivable configurations, with the advantage that nevertheless only a small fraction of the built-in photovoltaic system photovoltaic modules with the inventive functional modules must be equipped.

• a) Der Funktions-Modul 30 fragt beim nächstgelegenen Funktions-Modul an, damit dieser statt seiner eine Nachricht an die Analyse- und Steuereinheit schickt (sogenannte ”Relay”-Funktion);
• b) der Funktions-Modul 30 erkennt eine Störung und trennt den betreffenden DC-String auf. Dabei schickt er auch den anderen Funktions-Modulen den Befehl zum Auftrennen des Strings, wodurch eine weitere Verbesserung der Sicherheit bei Ausfall der Analyse- und Steuereinheit 56 geschaffen wird.

According to an advantageous development of the invention it can be provided that the function module sends an alarm data packet when exceeding the individually set threshold value of the temperature in such a way that it sends the currently measured temperature and the individually set threshold next to an alarm bit. The data packet is provided by the analysis and control unit 56 receive and notify the reception of the respective function module by sending a so-called acknowledge packet (ACK). If the correctly addressed function module does not receive the ACK, it will try to send the data packet several times after a certain timeout. If this is also unsuccessful, proceed as follows:

• a) The functional module 30 asks the nearest function module to send a message to the analysis and control unit instead of it (so-called "Relay"function);
• b) the functional module 30 detects a fault and disconnects the relevant DC string. He also sends the other function modules the command to split the string, thereby further improving the security in case of failure of the analysis and control unit 56 is created.

From the above description, it is clear that with the monitoring system according to the invention, a fire detection and localization is possible, which is characterized by a previously unattained monitoring security and speed, with the help of as few additional components. At the same time, however, due to the fact that the temperature sensors are integrated in a data communication network which is continuously checked for completeness, the monitoring system according to the invention can simultaneously serve as theft protection, with which it is determined not only whether a photovoltaic module has been stolen, but - due the detected ID of a module - also the location of the theft can be located and displayed.

By doing that, the individual function modules 30 equipped with an ID, the fire detection described above is already sufficient to detect a theft. However, it is equally possible, additional, so-called anti-theft detection modules (see 30 * in 3 ), similar to the functional modules 30 built and in addition to the function modules 30 in the individual DC strings 32-1 to 32-n in a similar way to the functional modules 30 are integrated. The power supply is similar to the function modules. Preferably, the stored ID data at predetermined time intervals, such. B. every 100 ms to the analysis and control unit 56 Posted. There, the stored ID data of these modules are checked for importance and presence. Missing z. B. an ID address, which can be attributed to a cable separation, so automatically by the software a search of this ID address is triggered. This process can be repeated several times in short time windows. If this ID address is not found, the software triggers a corresponding theft alarm.

The monitoring system may be further equipped with smoke and / or fine particulate detectors, which can further improve the monitoring accuracy. There are several alternatives for this Realization. For example, either separate smoke and / or fine particle detectors are provided or at least selected functional modules 30 additionally equipped with a smoke detector and / or a fine particle detector, wherein the output signals of the smoke and / or fine particle detector modules or smoke and / or a fine particle detector are additionally included in the monitoring of the solar system. It can also be done via a suitable interface connecting the monitoring system according to the invention to an existing fire alarm system.

In the case of theft protection, a so-called "relay" transfer method can optionally also be used. Each functional module 30 knows one or more adjacent function modules and can use them indirectly with the analysis and control unit 56 communicate. In this way, the location of a theft can be further improved.

According to a further embodiment or an advantageous development of the monitoring system according to the invention it can be provided that the programming of the individual modules and the analysis and control unit via the receiving and transmitting module 60 he follows. In this way, it is possible to change the evaluation logic of the monitoring system even after commissioning if necessary and, for example, to adapt to the changed environmental boundary conditions.

With the above-described assembly of a photovoltaic solar system according to the invention, the following advantages result:
First, the operator of a photovoltaic solar system can choose whether he wants to implement a fire alarm system, an anti-theft device or a combination of both tasks. Due to the composition of the monitoring system of modules, it is also possible to retrofit a system once set up, for example, for the fire control with little installation effort such that an improved anti-theft device is provided.

The fire protection monitoring can be carried out with the aid of the function modules 30 used temperature sensors in combination with an intelligent evaluation logic. However, it can be upgraded with additional monitoring criteria including particulate matter or gas measurements.

The emitted by the temperature sensors over time and continuously detected signals are evaluated on the basis of a preferably freely programmable evaluation pattern, which is tailored to the overall system, taking into account the existing geometric, constructive, material engineering and environmental parameters. This gives the monitoring method according to the invention an additional intelligence, which makes it possible to differentiate much more reliably than known systems between installation-related, harmless punctual temperature developments at individual positions of the solar system and the development of a dangerous situation. As a result, it is possible at the same time to classify a critical temperature development earlier than previously, because the tailored evaluation pattern evaluates the signals indicated by the temperature sensors over time, so that developments in critical situations can be detected at an early stage.

Not only the temperature distribution in the solar system, but also their development can be included according to the invention in the method for monitoring, making it more reliable than hitherto succeeding to make a statement about the actual safety status of the system.

The mode according to which the evaluation pattern is processed does not have to remain unchanged in the entire operating spectrum of the monitoring method. It is advantageous to configure the evaluation mode so that it can be up to a certain state point of the system, for example up to the time at which at least one temperature sensor reaches a signal threshold, at a simple level, such as on a event-driven level remains. Only then can the evaluation pattern pass into an evaluation mode in which the temporal development of the signals of the temperature sensors is evaluated individually and / or to one another. In this way, the signal flow can be minimized without having to accept significant functional impairments of the process.

Through the continuous query, storage and archiving of the measured data, a fire development can be documented and retrieved via a data communication module - also by remote inquiry - at any time. For this purpose, it may be advantageous to work with a separate readout box or a separate readout module, which allows only the police and / or fire investigators and / or fire insurance companies to read data. For the first time, only these target groups will have access to data that will allow reliable information on the development of a fire.

The fact that the individual modules are equipped with an electrical storage device, they remain self-sufficient and functional even if the power supply through the photovoltaic system fails.

The type of switching off of the photovoltaic solar system according to the invention completely eliminates the risk of injury due to high voltages (eg DC voltage current pulses and short-circuit arcs), since the system is disconnected from the AC mains in the critical case before the individual strings are short-circuited. Existing photovoltaic solar systems can be retrofitted with little effort to provide the functions of the monitoring system described above.

The monitoring system can additionally be combined with all conventional additional security systems, such as: B. with gas, smoke, water inlet detectors, etc.

The analysis and control unit is very flexible due to its programmability and can also be used to send in addition to alarm signals additional information that is of fundamental importance for fire protection, such. B. Details of where the access to an absolute shutdown of the system is located.

Of course, deviations from the described embodiments are possible without departing from the spirit of the invention.

The monitoring system can be equipped with additional control modules, each with a string 32-1 , ..., 32-n associated with the solar system and with which the respective assigned string by driving through the analysis and control unit 56 controlled separable, for example, for maintenance of the system.

The analysis and control unit 56 can be equipped with a security key that is connected via a data bus. This data bus can be followed by a reading device, which is accessible in this way only by a privileged group of people.

The system is also not limited to photovoltaic solar systems located on buildings. Rather, it is also possible to use this system to monitor pure solar parks as to whether critical thermal states are emerging at certain points.

• a) Analyse der Modulanordnung in Bezug zur Installationsumgebung unter Einbeziehung der vorliegenden Montage-Parameter;
• b) Auswahl aussagekräftiger Punkte, über deren Temperaturentwicklungen eine zuverlässige Aussage über das Vorliegen eines kritischen Zustands im Bereich der Anlage getroffen werden kann;
• c) Bestücken der diesen Punkten nahe kommenden Module mit Temperatursensoren; und
• d) Auswerten der von den Temperatursensoren über die Zeit abgegebenen Signale auf der Basis eines auf das System zugeschnittenen Auswertemusters.

The invention thus provides a method and a device for monitoring critical temperature developments in solar installations with photovoltaic modules, the method being characterized by the following steps:

• a) analysis of the module arrangement in relation to the installation environment, taking into account the present assembly parameters;
• b) selection of meaningful points over whose temperature developments a reliable statement about the existence of a critical condition in the area of the plant can be made;
• c) equipping the modules close to these points with temperature sensors; and
• d) evaluating the signals emitted by the temperature sensors over time on the basis of an evaluation pattern tailored to the system.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 202006007613 U1 [0003]
• DE 102005018173 B4 [0004]
• WO 2010/031394 A1 [0005]
• WO 2009/026602 A1 [0005]
• WO 2007/041693 A2 [0005]
• EP 2136411 A1 [0005]
• EP 1587148 A1 [0005]
• DE 102008008504 A1 [0005]
• DE 102008003272 A1 [0006]

Claims (33)

Method for monitoring critical temperature developments in solar installations with photovoltaic modules, comprising the following steps: a) analysis of the module arrangement in relation to the installation environment, taking into account the present installation parameters such as installation location, size, geometry, intrinsic structure, topography and orientation; b) selection of meaningful points (X) over whose temperature developments a reliable statement can be made about the existence of a critical condition in the area of the installation; c) equipping the modules close to these points ( 12-1 . 12-2 , ..., 12-n ) with temperature sensors ( 28 ); and d) evaluating the signals emitted by the temperature sensors over time on the basis of an evaluation pattern tailored to the system. A method according to claim 1, characterized in that the evaluation of the signals of the temperature sensors takes place in such a way that at the latest when reaching a signal threshold value at least one temperature sensor ( 28 ) passes the evaluation pattern in an evaluation mode in which the temporal evolution of the signals of the temperature sensors ( 28 ) is evaluated individually and / or to each other. Method according to Claim 2, characterized in that the signal threshold values of the temperature sensors ( 28 ) are set individually according to the present mounting parameters. Method according to one of claims 1 to 3, characterized in that the signals of the temperature sensors are processed centrally and preferably stored with a time stamp. Method according to one of claims 1 to 4, characterized in that the temperature sensors ( 28 ) into a data communications network ( 32 ), which is constantly checked for completeness. Method according to Claim 5, characterized in that the direct current supply network ( 32 ) of the photovoltaic modules ( 12-1 . 12-2 . 12-n ) is used as part of the data communication network. Method according to one of claims 1 to 6, characterized in that upon reaching a critical state of the solar system, the individual strings ( 32-1 , ..., 32-n ) are separated. Method according to claim 7, characterized in that the relevant string ( 32-1 , ..., 32-n ) is short-circuited after disconnecting. Method according to one of claims 1 to 8, characterized in that the temperature sensors ( 28 ) each into a function module ( 30 ) are integrated with the upon reaching a critical state of the solar system and / or according to a control signal of a control center ( 54 ) selected strings ( 32-1 , ..., 32-n ) of the solar system can be shorted. A method according to claim 9, characterized in that the solar system before separating at least one selected string ( 32-1 , ..., 32-n ) from the network ( 68 ) is taken. Method according to claim 9 or 10, characterized in that the functional module ( 30 ) in the connecting line of two adjacent photovoltaic modules ( 12-1 ) is integrated. Method according to one of claims 1 to 11, characterized in that it is combined with an existing fire alarm system or with additional smoke or fine particle detector modules, for example, either using separate smoke detectors or fine particle sensors, or selected functional modules ( 30 ) are equipped with a smoke detector or fine particle sensor whose signals are also included in the monitoring of the solar system, or via a suitable interface, a connection to an existing fire alarm system. Device for monitoring critical temperature developments in solar systems with photovoltaic modules, in particular for carrying out the method according to one of claims 1 to 12, with a multiplicity of temperature sensors ( 28 ), which are distributed in the solar system in such a targeted manner that they are each at least close to points (X), their temperature development including installation parameters of the solar system, such as installation environment, size, geometry, intrinsic structure, topography and orientation, a sufficiently meaningful Statement about the existence of a critical condition in the area of the installation, and a data communication network ( 32 ), via which the measuring signals of the temperature sensors ( 28 ) an analysis and control unit ( 56 ), with which the temperature sensors ( 28 ) can be evaluated over time based on a pattern tailored to the system. Apparatus according to claim 13, characterized in that the analysis and control unit ( 56 ) clocked the individual temperature sensors ( 28 ) controls and stores the received signals preferably with a time stamp. Apparatus according to claim 13 or 14, characterized in that the analysis and control unit ( 56 ) works with a preferably freely programmable evaluation logic, via which the evaluation of the measurement signals and the control of the temperature sensors ( 28 ) taking into account the temporal evolution of the signals of the temperature sensors ( 28 ) individually and / or to one another. Device according to one of claims 13 to 15, characterized in that the temperature sensors ( 28 ) in each case an address (ID) is assigned. Device according to one of claims 13 to 16, that the direct current supply network ( 32 ) of the photovoltaic modules ( 12-1 , ..., 12-n ) is used as part of the data communications network (12) by modulating the measurement and control signals over the DC cabling of the photovoltaic modules (12). Device according to one of claims 13 to 17, characterized in that the temperature sensors ( 28 ) each into a function module ( 30 ) integrated in the solar system in such a way that it is able to 32-1 , ..., 32-n ) of the solar system. Apparatus according to claim 18, characterized in that the functional module ( 30 ) is integrated into the solar system such that its associated string ( 32-1 , ..., 32-n ) upon reaching a critical state of the solar system and / or according to a control signal of the analysis and control unit ( 56 ) can be separated and shorted. Device according to claim 18 or 19, characterized in that each functional module ( 30 ) is assigned an individual, preferably adjustable or programmable temperature threshold, and that the function module ( 30 ) upon reaching this temperature threshold, a signal to the analysis and control unit ( 56 ), with which the control mode of the device passes from an event control to a control according to the "polling" principle, in which the status of the function modules ( 30 ) and / or the signals of the temperature sensors ( 28 ) is detected by means of cyclic queries. Device according to one of claims 18 to 20, characterized in that the functional module ( 30 ) in the connecting line ( 32 ) of two adjacent photovoltaic modules ( 12-1 . 12-2 ) is integrated. Device according to one of Claims 18 to 21, characterized by additional control modules, each of which is a string ( 32-1 , ..., 32-n ) are associated with the solar system and with which the respective assigned string by driving through the analysis and control unit ( 56 ) separable and / or closable. Device according to one of Claims 13 to 22, characterized by a network ejection module ( 64 ), with which the solar system is controlled by the analysis and control unit ( 56 ) before separating the individual strings ( 32-1 , ..., 32-n ) in the AC sector ( 68 ) is removable from the network. Device according to one of claims 13 to 23, characterized in that the device is additionally equipped with smoke and / or fine particle detector modules, for example by either separate smoke and / or fine particle detectors are provided, or at least selected function modules ( 30 ) are additionally equipped with a smoke and / or a fine particle detector, wherein the output signals of the smoke and / or fine particle detector modules or smoke and / or a fine particle detectors are also included in the monitoring of the solar system, or via a suitable interface a connection to an existing fire alarm system takes place. Device according to one of claims 13 to 24, characterized by a modular construction, wherein between the functional modules ( 30 ) and the analysis and control unit ( 56 ) one preferably for all strings ( 32-1 , ..., 32-n ) competent string coupling module ( 52 ), which is preferably connected via a data bus ( 54 ) with the analysis and control unit ( 56 ) connected to the analysis and control unit ( 56 ) converts incoming data into a modulated signal and that of the function modules ( 30 . 30 * ) demodulates incoming signals. Apparatus according to claim 25, characterized in that the string coupling module ( 52 ) between photovoltaic modules ( 12-1 . 12-2 ) and the inverter (s) ( 66 ) of the solar system is placed. Device according to one of Claims 13 to 26, characterized by a data module in which the network connection software and the communication software are contained and which contains the link and the interface for the analysis and control unit ( 56 ) for data transmission in an analogue / digital network and / or in the Internet and preferably with a receiving and transmitting module ( 60 ), with which the preferably wireless, for example, via GSM radio running communication of the analysis and control unit ( 56 ) is feasible to peripheral stations. Device according to one of claims 13 to 27, characterized in that the internal and / or the external data communication is encrypted. Device according to one of claims 18 to 28, characterized in that the functional modules ( 30 . 30 * ) and / or the additional control modules and / or the network ejection module ( 64 ) and / or the string coupling module ( 52 ) and / or the analysis and control unit ( 56 ) are supplied by the operating voltage of the solar system, wherein in addition an electrical energy storage ( 48 . 72 ), such. B. a Li-ion battery an emergency power supply in split strings ( 32-1 , ..., 32-n ). Use of the device according to one of claims 13 to 29 for fire and / or theft monitoring. Function module for use in a device according to one of claims 13 to 29, with a metallic, preferably fully encapsulated housing ( 34 ), to which for attachment to a supporting structure ( 24 ) of the photovoltaic modules ( 12-1 . 12-2 ) a mounting tab ( 36 ) is formed, which in the interior of the housing a temperature sensor ( 28 ) wearing. Function module according to claim 31, which accommodates the following components inside the housing: a microcontroller (μC) ( 40 ) controlling the data communication via a modulator / demodulator ( 42 ), measuring the temperature, the electronic separation of the string ( 32-1 , ..., 32-n ) and preferably performs a diagnostic and analysis function relating to the power supply and / or the signal quality, - a modulator / demodulator ( 42 ), by which the microcontroller ( 40 ) are converted into a modulated signal, - a coupling element ( 50 ), with which the modulation signals can be switched on and off on the DC voltage lines, - a breaker ( 44 ), such. B. an electrical switch or relay contact, to break the string ( 32-1 , ..., 32-n ) under the control of the analysis and control unit ( 56 ), - a mechanical opener, such. B. a bimetallic switch with which at too high a temperature of the string ( 32-1 , ..., 32-n ) autarkic separable, and - an electrical energy storage ( 48 ), is provided with the electrical energy for supplying the functional module in the case of non-existent DC voltage from the solar system. Functional module according to Claim 32, in which a coupling element (in each case on both sides of the breaker ( 50 ) is provided.

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