DE102009044695A1 - Solar module, modular switch, solar cable, busbar, multi-contact connector - Google Patents

Abstract

This invention relates to solar modules (24, 64, 74, 84, 94) with at least two solar cell strings (25, 65, 75), each string being galvanically isolated from the other strings. The invention further relates to solar modules, such as a series diode (26), for example a Schottky diode, which is connected in series with the solar cells of the string, so that the voltage supplied by the solar cells poles the series diode in the direction of flow. In addition, the invention relates to module switches. A module switch comprises a control input (111) and a switching output (116) for short-circuiting a solar module ring. If an electrical signal is present at the control input (111) above the threshold value, the two electrical connections of the switching output (116) are connected to each other with low resistance, otherwise with high resistance. The invention also relates to solar cables with a plurality of electrical conductors which are insulated from one another. The invention further relates to busbars (8, 9) for solar systems which have connectors for solar cables (33, 34, 35) with a plurality of electrical conductors. Finally, the invention relates to multi-contact connectors for solar cables.

Description

The field of the invention is photovoltaic systems and in particular solar modules.

Photovoltaic has been used successfully for more than 50 years, first as a power supply in space technology, then in experimental facilities and due to government incentives in ever greater numbers and with increasing performance of individuals. Nominal values of current and voltage have meanwhile increased considerably and with it the effects of an arc fault.

A circuit diagram of a conventional photovoltaic system 1 is in 29 shown. It usually consists of a photovoltaic generator 2 and one or more inverters 3 or charge controllers, unless the consumer is directly from the photovoltaic generator 2 is fed. This document contains an inverter 3 always exemplary for multiple inverters, one or more charge controller or one or more other consumers and can be replaced by this. The photovoltaic generator 2 is mostly made up of several solar modules 4 built in series with one or more strings 5 are interconnected. When operating multiple strings 5 at a common inverter 3 or charge controllers can use the strings 5 parallel via two busbars 8th and 9 be interconnected. In this case, to exclude reverse currents in a string, each string has a series diode 6 , A fuse 7 in each string, the corresponding string should be removed from the rest of the photovoltaic system 1 separate. Bypass diodes in the solar modules carry the current of the unshaded modules of the string in case of shading of the module.

Usually all solar cells within a module are connected in series to keep the number of external contact points low. In 30 is a solar module 14 with several substrings 15 within the solar module 14 shown, where the substrings 15 are not led out individually, but in the junction box 17 are connected in parallel. In another embodiment according to the prior art, the substrings 15 also be connected in parallel in the cell array. As a result, many modules have nominal current intensities> 5 A in the 150 mm × 150 mm solar cells now used. The bypass diode 18 in the solar module 14 in case of shading of the module carries the stream of unshaded modules of the string.

31 shows a circuit diagram of a solar module 14 ,

In the systems, only inadequate arrangements for arc protection are usually made. There are now improved connectors and junction boxes. The measures are essentially aimed at reducing the probability of default at the contact points such. B. optimized plug contacts and the prevention of water ingress as well as a reduction in the arc consequences such. B. Junction boxes made of aluminum ( Elektroprofi 2/2008, p. 43-45 ). There are also special UV-resistant solar cables and cable ties. In addition, the isolation of solar cables from an arc-inhibiting material, for. B. from irradiated polyamide 66 consist. If an arc occurs, the arc-inhibiting material will escape and / or evaporate partially. Thus, the arc plasma is deprived of energy and the arc extinguished. All these measures can not avoid the actual arc.

An arc in the system can be detected ( US 2006/0171085 A1 . US 6,259,996 B1 . US 6,633,824 B2 , especially for photovoltaic systems: WO 95/25374 A1 ), but until now there is no way to react to the arc in a photovoltaic system. How to use switchgear in photovoltaic systems to respond to an arc is in I. Müller: "Arc fault protection in the DC part of photovoltaic systems", Wissenschaftsverlag Ilmenau, 2002, ISBN: 3-936404-02-X (hereinafter: Müller02). There, whole strings are switched. In addition, in EP 1 709 504 B1 the method described in Müller02 used on solar sources of spacecraft.

An inherently effective method that can avoid the arc is based on the use of capacitors and is in the WO 2004/010556 A3 described. Unfortunately, due to the high temperatures on the roof when exposed to solar radiation, the capacitors required for this purpose can not be procured on the market with sufficient life expectancy. But they could be developed.

The photovoltaic generator is by DC switch disconnector after DIN VDE 0100-712 , which is usually present only on the inverter, can be switched off. The modules are then still under tension, so that for acting in the vicinity of the plant persons z. B. during assembly or fire a hazard can not be excluded.

The US 2009/0114263 A1 discloses switchable modules that break the module contact to the rest of the system by means of a switching device used in series (contact or electronic). This can not be used at higher string voltages, because the first opening contact always contains the entire string voltage (U _LL -U _MPP ; open circuit voltage at the point of maximum power; see UI characteristic for module, 2 ) sees, therefore is claimed considerably and must be sized accordingly.

Usually, the module junction boxes have a single volume, in which all contact points are embedded on a common terminal block.

Solar cables only consist of a single core.

Usually, the solar cells are embedded in EVA (ethylene-vinyl acetate). The rear wall consists of a more or less flammable plastic.

It is an object of the invention to provide safe solar modules, module switches, safe solar cables, secure busbars and secure connectors.

This object is achieved by the teaching of the independent claims.

Preferred embodiments of the invention are subject of the dependent claims.

In the following, a preferred embodiment of the invention will be explained in more detail with reference to the accompanying drawings. Showing:

1 a solar module according to the invention;

2 the characteristics of a single string arrangement and different length arcing;

3 the characteristics of a string of a multi-string arrangement and different length arcing;

4 and 5 solar modules according to the invention;

6 and 7 the construction of photovoltaic systems according to the invention;

8th the construction of a photovoltaic system according to the invention in fishing net topology;

9 a general, inventive module switch;

10 to 14 various embodiments of a module switch according to the invention, in which the electrical isolation and the short-circuiting of the solar modules is effected by relays;

15 to 18 various embodiments of a module switch according to the invention, in which the short-circuiting of the solar modules by an NPN transistor takes place;

19 to 22 various embodiments of a module switch according to the invention, in which the short-circuiting of the solar modules is performed by a PMOS;

23 a topology in which two out of phase control signals are used;

24 and 25 Embodiments of a module switch according to the invention for 2 antiphase control signals;

26 and 27 Solar cable according to the invention;

28 a cross section through a solar module according to the invention;

29 a circuit diagram of a conventional photovoltaic system;

30 a solar module with several substrings; and

31 a switching symbol of a solar module.

1 shows a solar module according to the invention 24 that made of a solar cell array 22 and a module junction box 27 consists. The solar cell array 22 includes the solar cells 21 that is in a one-dimensional array of multiple substrings 25 are interconnected. Each substring 25 consists of a series connection of several solar cells 21 , Each substring 25 has a positive connection 30 and a minus connection 31 on. The plus connection 30 is at the same time the anode connection of in 1 to Colonel represented solar cell of the corresponding substring. The negative connection 31 is the cathode terminal of in 1 at the bottom illustrated solar cell of the corresponding substring. In addition, each substring 25 one or more taps 32 have the substring 25 divide into substring sections. Each partial string section in a solar cell array 22 contains in one embodiment the same number of solar cells 21 , Each partial string section has a bypass diode 28 switched in anti-parallel. In addition, a switching element is for each Teilstringabschnitt 23 connected in parallel, which shorts the Teilstringabschnitt when the switching element is not controlled by a control 29 is opened for normal operation. The switching elements 23 can be called "normally closed". In the following, the open high-resistance state of the switching element 23 as the operating state and the closed state as the ground state.

In the in 1 illustrated embodiment, all bypass diodes 28 , all switching elements 23 as well as the control 29 in the module junction box 27 accommodated. As a result, existing solar modules can be retrofitted at least partially. For this it is necessary that the contacts between the solar cell array 22 and the module junction box 27 easily separable, so for example pluggable realized via a plurality of plugs and corresponding sockets, which are mechanically connected to each other in the solar cell array and in the module junction box. On the other hand, this requires that not only the positive terminals 30 and the minus connections 31 to the module junction box 27 need to be guided, which is required anyway, but also all taps 32 ,

To get better heat dissipation from the bypass diodes 28 and the switching elements 23 and also to the cable management in the solar module 24 To simplify, in another embodiment, the bypass diodes 28 and the switching element 23 distributed over the solar module be mounted. In this embodiment, the connections between the solar cell array 22 and the module junction box 27 hardwired, which should be cheaper and more reliable.

In the module junction box 27 are also serial diodes 26 housed, with a series diode 26 in series with each substring 25 is switched. The series diodes 26 are only at an in 8th required fishing net topology required. There is a plussolar cable at the module junction box 33 and a mini solar cable 34 connected. Also the connection between the solar cables 33 and 34 and the module junction box 27 can be either solid or solvable. In the case of a detachable connection, each solar module 24 with two preassembled solar cables 33 and 34 to be delivered. Each of the solar cables 33 and 34 points for each substring 25 an electrical conductor 36 on that with the appropriate substring 25 electrically connected. Every solar cable 33 and 34 indicates the loose end where it is not connected to the module junction box 27 connected to a contact point, leaving the loose end of a plussolar cable 33 with the loose end of a minus solar cable 35 another solar module or the plus busbar can be connected. Contact or point of contact is used in this document as a generic term for plug and socket.

How to get out 29 . 6 . 7 and 8th recognizes, are the solar modules 4 connected in series to form strings 5 , This is done in a conventional manner, so that when installing a solar cable the newly installed solar module is connected to a solar cable of the previously mounted solar module. The solar modules according to the invention 24 So can advantageously as well as the conventional solar modules 4 to be assembled. For reasons of better heat dissipation from the switching elements and / or string diodes and the better thermal stability, it is advantageous to the module junction boxes 27 made of metal, especially aluminum.

Important for one aspect of the invention is that all substrings 25 of a solar module against each other electrically isolated, so are electrically isolated. Even after the assembly of all solar modules according to the invention 24 a photovoltaic generator 2 In one embodiment of the invention, the partial strings are 25 only on the. busbars 8th and 9 connected in parallel.

Bypass diodes 18 are known at the solar module level, as in 25 shown. The provision of a bypass diode 28 For each partial string section results in more favorable behavior with partial shading of the module, because only the actual (partially) shaded partial string sections fail and no longer the entire module. In this respect, the division of a module into partial strings or partial string sections is the prerequisite for better performance with partial shading. As bypass diodes 28 and / or series diodes 26 For example, Schottky diodes can be advantageously used because of the lower forward voltage. The lower forward voltage reduces the heat dissipation requirements while increasing efficiency.

The aim of the division into substrings is to reduce the currents in the live conductors and provided and not provided contact points. Provided contact points may be, for example, connectors. Unintended contact points are fault locations, that is, for example, bad, corroded contacts or wire breaks. As is known from Müller02, the conditions of existence for an arc deteriorate when the current in a string or substring decreases. At a current <2 A, the arc already burns significantly more unstable than at 5 A or 8 A, below 0.5 A, it can no longer exist because the amount of charge carriers generated is no longer sufficient to maintain an arc discharge. Conveniently, one chooses a partial current <1 A as a compromise between deterioration of the conditions of existence and costs.

Compared to the single-string arrangement, in the case of the multi-string arrangement with the same nominal power, only significantly smaller arc lengths with significantly smaller power over the fault location are possible, if at all.

As an additional measure against transverse defects is in 1 each contact to a vein of the plus and minus solar cable in a separate chamber 38 accommodated. Thus, a sufficient insulation of the contacts is more likely, even if the cable insulation is brittle or loose contact points.

On the example of 2 and 3 the operating principle for a split into 8 partial strings with a total of the same power and identical rated voltage is clarified. In the 2 and 3 is up the string or substring voltage and drawn to the right of the string or Teilstringstrom. In the 2 and 3 are three characteristics 42 . 43 and 44 of arcs for different arc lengths l ₁ , l ₂ and l ₃ registered. In 2 is also a characteristic 41 a conventional solar module with a single string and about 5 A current at the point of maximum power 45 in which the solar module is normally operated, which corresponds to about 8 A short-circuit current l _k . Out 2 It can be seen that an arc of length l ₁ with a stable operating point 46 can exist. As well as the characteristics 43 and 44 the characteristics 41 also arcs with a longer length l ₂ or l _{3 may} exist.

In 3 is the characteristic 51 drawn for a substring, which provides only one-eighth of the stream of the single string whose characteristic 41 in 2 is shown. The point of maximum power 55 is at the same voltage U _MPP as the point 45 but only at one-eighth of the current. The short-circuit current of the substring in 3 is about 1 A. An arc of length l ₁ can only in the small area above the point 56 exist. Arcs of length l ₂ and l ₃ may lack of an intersection of the characteristics 43 and 44 with the characteristic 51 does not exist. If one were the number of substrings of 8th on 9 increase and thus reduce the current by about 11%, no arcs of length l _{1 would} be possible. Compared to the conventional single-string arrangement in 2 With the multi-string arrangements, if at all, only considerably smaller arc lengths with significantly smaller power over the fault location are possible.

4 shows a solar module 64 that the in 1 illustrated solar module 24 is similar. In essence, the substrings were 25 , in the 1 through the series-connected solar cells 21 are represented by circuit diagram for solar modules 65 replaced. Each substring 65 can total about a switching element 63 be closed briefly, since it consists of only one section. The switching elements 63 be from a control 29 controlled. Also the series diodes 26 are shown explicitly. Bypass diodes can be part of the substrings 65 be. All connections to a plussolar cable and all connections to a mini solar cable are in 2 separate chambers 69 respectively. 68 accommodated.

5 shows a new circuit diagram for a solar module according to the invention 74 , The solar module contains H substrings 75 that are under control of the control 29 can be closed for a short time. It is not specified whether as in 1 individual Teilstringabschnitte by switching elements 23 can be closed briefly or if as in 4 each partial string through a corresponding switching element 63 can be closed for a short time.

6 shows the structure of a photovoltaic system according to the invention 81 with a photovoltaic generator according to the invention 82 and an inverter 3 , Unlike a conventional photovoltaic generator 82 is a serial diode for each substring 86 as well as a fuse 87 intended. The individual substrings are first on the busbars 8th and 9 electrically connected.

In the 6 illustrated solar modules according to the invention 84 have neither switching elements for shorting the substrings or Teilstringabschnitte nor a control. The busbars should be easy to install 8th and 9 with multipole contact points 88 . 89 be equipped for multi-pole solar cable.

7 shows the structure of a photovoltaic system according to the invention 91 with a photovoltaic generator according to the invention 92 and an inverter 3 , Unlike the in 6 shown solar modules have the solar modules 94 in 7 Switching elements and one control each 29 on. All control inputs of the controls 29 are connected in series. In addition, one or more emergency switches 95 and a control signal source 96 provided in normal operation the controls 29 supply with electrical energy, so that the individual substrings or Teilstringabschnitte the solar modules are not shorted. In a fire, the fire department can emergency switch 95 open or connect 97 disconnect, whereby the substrings or partial string sections are closed briefly, so that a safe Löscheinsatz is possible. The emergency switch or switches can also be designed as thermal fuse or thermal fuses, so that the solar system is switched off automatically at too high a temperature in one place. The control signal source 96 is usefully executed as a power source to photovoltaic generators 92 with a different one. Number of solar modules 94 to be able to control.

For ease of installation, the busbars should also be here 8th and 9 be equipped with connectors for multi-pole solar cable. The wiring in the connectors and between the busbars is a bit more complicated than in 6 because yes all the controls 29 to be connected in series and thus also electrical connections 97 between the at the busbars 8th and 9 attached connectors are needed.

In another embodiment, only the controls may be used 29 a string into a control string in series. All control strings are then switched in parallel. In this case, the control signal source for a given number of series-connected solar modules can also be designed as a voltage source or you can adjust the voltage supplied by the control signal source step by step to the number of solar modules in a string. If the control signal source operates as a current source, in this embodiment also the height of the control current can be adjusted stepwise to the number of strings.

The control signal source can its energy on the one hand via the lines 99 from the power grid and thus also from the inverter 3 Respectively. Additionally or alternatively, the control signal source 96 also with the DC power circuit of the photovoltaic system 91 So with the busbars 8th and 9 over the wires 98 be connected. If the wires 99 lacking, there is the problem that the solar modules provide too low a voltage during the day when the switching outputs 116 the module switches are in low-impedance state, so if the photovoltaic system 91 is in the ground state. If, on the other hand, by meaningful design of the switching outputs ensures that, despite the ground state at the busbars for non-hazardous voltage in the range of about 10 V is applied, you can for example by a DC-DC converter with another input voltage range from this residual voltage, a sufficiently strong control signal generate, so by closing the or any emergency switch 95 the photovoltaic system 91 can put in the operating state. Due to the residual voltage in the ground state, the photovoltaic system 91 self-sufficient.

The emergency switch 95 can also be the control signal source 96 be installed. The control signal source 96 May possibly together with an emergency switch 95 also in the inverter 3 or a charge controller. The latter integration is also advantageous because the inverter 3 or the charge controller the photovoltaic generator 92 can switch off even if a defect in the inverter 3 or charge controller or overheat these devices.

8th shows the structure of a photovoltaic system according to the invention 101 with a photovoltaic generator according to the invention 102 in fishing net topology and an inverter 3 , Unlike the in 6 Topology shown are additional busbars 108 provided as cross connections between the individual substrings. With this, it is possible to ensure that no arc burns throughout the entire network. If the nominal module voltage is limited to values <15 V, a stable arc can no longer exist if there is a transverse fault across a module. An arc in the case of a longitudinal fault is already excluded for module rated voltages <55 V, because in this fault, the difference between open circuit voltage and maximum power voltage represents the maximum available voltage for the arc. The fishing net topology is also suitable for the known embodiments of solar modules.

9 shows a general module switch 110 with a control 29 and a switching element 113 , The module switch 110 is a quadrupole with a two-pole control input 111 and a two-pole switching output 116 , which is connected in parallel to a string or substring, by the switching element 113 can be closed for a short time. The control 29 includes a signal receiving circuit 112 and a driver stage 114 , where the signal receiving circuit 112 and the driver stage 114 are coupled galvanically isolated. The signal receiving circuit 112 is with the control input 111 electrically connected. The driver stage 114 is with the switching element 113 coupled. In the following and in the 10 - 21 illustrated embodiments of a module switch is no longer distinguished between substring and string, but string used as a generic term for string and substring.

• 1) Die galvanische Trennung kann realisiert sein: a) (elektro-)magnetisch durch – einen Magnetkreis mit Kontakten, nämlich einem elektromechanischen Relais, vorzugsweise einem Reed-Relais oder – einem Magnetkreis mit Hallelement oder b) optisch durch A) einen Optokoppler mit diskreten Bauelementen, nämlich. i) einem Sender, der beispielsweise aus einer Glühlampe, Leuchtdiode (LED) oder Gasentladungslampe bestehen kann und ii) einem Empfänger, der beispielsweise aus einem Fotothyristor, einem Fotowiderstand, einer Fotodiode oder einem Fototransistor bestehen kann oder B) als integriertes Bauelement, das Sender und Empfänger enthält. c) induktiv durch einen Transformator, auch einen mehrphasigen Transformator oder induktiv gekoppelte Resonanzkreise, die letztlich auch einen Transformator darstellen; d) kapazitiv mittels einer Kondensatoranordnung.

Optionally, the module switch 110 another display element 117 contained, which is advantageously supplied with solar energy from the string. Optionally, the display element 117 a display output 118 have over which the state of the switching element is wired or wirelessly transmitted to a remote display device and displayed there. The remote display device may be, for example, in the inverter 3 are located.

• 1) The galvanic isolation can be realized: a) (electro) magnetic by - a magnetic circuit with contacts, namely an electromechanical relay, preferably a reed relay or - a magnetic circuit with Hall element or b) optically by A) an opto-coupler with discrete components, namely. i) a transmitter, which can consist of an incandescent lamp, light-emitting diode (LED) or gas discharge lamp, for example, and ii) a receiver, which can consist of a photothyristor, a photoresistor, a photodiode or a phototransistor, for example, or B) as an integrated component, the transmitter and receiver contains. c) inductively by a transformer, also a multi-phase transformer or inductively coupled resonant circuits, which ultimately represent a transformer; d) capacitively by means of a capacitor arrangement.

• e) DC/DC-Wandler besonders, zur Ansteuerung von MOSFETs, aber auch Bipolar-Transistoren;
• f) Isolationsverstärker;
• g) Halbleiterrelais (Solid-State-Relais).

In addition, components are possible which already contain a galvanic separation:

• e) DC / DC converter in particular, for driving MOSFETs, but also bipolar transistors;
• f) isolation amplifier;
• g) Solid state relay (solid state relay).

• h) Ansteuerung mit optischem (Glasfaser-)Kabel;
• i) Spulenanordnung mit/ohne Kern (z. B. Rahmenspule im Modul und Induktionsschleifen im Generator)
• k) elektromagnetisches Feld (Funk) ohne oder mit Protokoll (z. B. Bluetooth, ZigBee, WLAN, RFID).

Finally, there are special cases in which there is a spatial division of the galvanic separation:

• h) control with optical (fiber) cable;
• i) Coil arrangement with / without core (eg frame coil in the module and induction loops in the generator)
• k) electromagnetic field (radio) without or with protocol (eg Bluetooth, ZigBee, WLAN, RFID).

Series and parallel circuits in the signal receiving circuit of the control of a module, preferably in windings (relays) and optocoupler transmitters are possible (see. 13 ). But also in the output of the driver stage, if several switching elements are to be controlled.

The control circuit can be operated with DC and / or AC voltage. When alternating voltage is used, rectification and screening may be necessary (cf. 19 ). The transmission of the control signal can also be conducted with a transmission protocol (eg CAN bus). This requires the use of sequential circuits or even microcontrollers in the control. Even when using transmission protocols, it should be checked whether a valid protocol is available. If this is not the case (loss of signal), the module switch should, as a precaution, change to the non-hazardous basic state. This corresponds to the comparison with a threshold if the module switch is controlled with DC and / or AC voltage or current.

The galvanic isolation can also be done with multiple isolation links in chain circuit, for example by the combination of transformer and optocoupler.

A DC / DC converter with wide-voltage input range of z. B. 1-60 V, if necessary, with extra stabilization, can be provided for self-supply of the control using the power produced by the module itself.

Conveniently, the control contains threshold behavior and hysteresis, so that the switching element does not leave the safe working area in the output characteristic field.

As a threshold and / or driver stage operational amplifier can be used.

• 2) Das Schaltelement kann als elektrisch bedienbarer Kontakt oder steuerbarer Halbleiter ausgeführt sein, also beispielsweise a) ein Kontakt, der Teil eines Relais, vorzugsweise eines Reed-Relais, ist; b) ein Bipolartransistor; c) ein Feldeffektransistor, z. B. ein MOSFET selbstleitend oder selbstsperrend; d) ein IGBT (Insulated Gate Bipolar Transistor); e) ein Thyristor, beispielsweise mit Hilfskreis zur Löschung; f) ein Triac, beispielsweise mit Hilfskreis zur Löschung;

The control signal and the signal receiving circuit can also be multi-phase, in particular out of phase, designed. This can increase the noise immunity.

• 2) The switching element may be embodied as an electrically operable contact or controllable semiconductor, that is, for example, a) a contact which is part of a relay, preferably a reed relay; b) a bipolar transistor; c) a field effect transistor, e.g. B. a MOSFET self-conducting or self-locking; d) an IGBT (Insulated Gate Bipolar Transistor); e) a thyristor, for example, with auxiliary circuit for deletion; f) a triac, for example with auxiliary circuit for deletion;

In the basic state (solar radiation on module, no control signal), the switching element is closed; either by execution as a normally closed contact (normally closed) or by a self-holding circuit. At the externally accessible terminals of the module is then at a safe voltage, which is significantly lower than the rated voltage of the module, ie 0 V to a few volts. It is possible to realize <3 V over a single module switch. The advantage of short-circuiting unlike patent US 2009/0114263 A1 with switching contact in series with the module is that over the switching path is not applied substantially more than the open circuit voltage of the string (see. 2 , Curve 41 ).

• 3) Das optionale Anzeigelement zur Anzeige des Betriebszustandes eines Strings kann eines oder mehrere der folgenden Bauteile umfassen: a) eine LED b) eine Glühlampe c) ein Gasentladungselement d) ein Koppelelement (z. B. Optokoppler) zur Übertragung des Zustandes an eine entfernte Anzeige oder Auswerteeinheit.

The switching element can also be realized by combining several switching elements in the form of a series or parallel connection or by push-pull or bridge circuit. The provision of the corresponding necessary voltage potentials and control currents is ensured by the driver stage.

• 3) The optional display element for indicating the operating state of a string can comprise one or more of the following components: a) an LED b) an incandescent lamp c) a gas discharge element d) a coupling element (eg optocoupler) for transmitting the state to a remote one Display or evaluation unit.

The display element may be coupled to control signal circuit, driver stage and / or switching element and display current and / or voltage values.

Display for the switching state preferably on the sunny side of the module, but can also be mounted on / in junction box. For example, with extra holes for LED or translucent housing (construction) parts of the junction box such. B. the can lid.

The display element can also Fensterdiskriminatorverhalten, z. B. display a voltage value of 1.5 V to 3 V, have.

If you want to retrofit existing solar modules with modular switches for safety reasons, the module switches should be prepared for this task. This can be achieved in a simple manner in that the two poles of the switching output 116 be carried out twice, so that at each pole, a connection for a string of solar cells and a solar cable is available.

10 shows an embodiment of the module switch 120 in which the control 122 and the switching element through a relay with relay coil 131 and normally closed contact 123 be formed. A diode 132 short-circuits induction voltages, as when switching off the current through the relay coil 131 occur. In the ground state is the normally closed contact 123 closed, ie the module voltage is near 0 V, ie <3 V. About the shunt resistor 133 (0.47 Ω), a low voltage drops to exceed the series resistance 135 (27 Ω) the LED 134 be supplied with electricity and let it shine. But the operating state can also be via the LED 138 are displayed, which via the tens diode 136 and the series resistance 137 (2.2 k Ω) is powered. The breakdown voltage of the Zener diode 136 is greater than the tension on the string 115 in the ground state, ie> 3 V, so that in the ground state certainly no current through the LED 138 flows and with it the LED 138 certainly not lit.

It is safer to explicitly display only a dangerous condition because a display device may also be defective. If nothing is displayed, it is always assumed that there is a danger, as it also occurs when using the previously used modules. So if only one LED is to be used, the LED is 134 to give preference. If the fire brigade sees in this embodiment, the module lights up, they can in the event of a fire without hesitating to delete water Against this background, the LED 134 green for the ground state and the LED 138 be red for the operating state. The colors can be awarded in other embodiments but also different. The light of the LEDs can also be transmitted via fiber optic cable to a remote display, for example in or at the charge controller.

• a) sie gestatten verblüffend einfache und kostengünstige Lösungen mit großem Störabstand (Sicherheitsrelevantes Bauelement)
• b) es tritt nur eine relativ geringe Verlustleistung in der Anschlussdose durch die ohmschen Verluste der Relaiswicklung auf. Auf eine zusätzliche Kühlung kann dadurch meist verzichtet werden.

Relays have two advantages over purely electronic solutions:

• a) they allow astonishingly simple and cost-effective solutions with a large signal-to-noise ratio (safety-relevant component)
• b) there is only a relatively low power loss in the junction box by the resistive losses of the relay coil. An additional cooling can be dispensed with mostly.

The wear caused by the mechanical parts and the contacts is of minor importance in the few expected switching operations.

The components in the display element 127 can also be omitted. Then the shunt resistor 133 be replaced by a ladder. This reduces the power loss occurring in the module junction box.

11 shows a module switch 140 that is different from the module switch 120 only through the optocouplers 141 and 142 (both for example MB104C) differs. The LEDs 134 and 138 are in the module switch 140 Part of the optocoupler 141 and 142 , The phototransistor of each of the two optocouplers 141 and 142 forms a display output 143 respectively. 144 , Corresponding display outputs of the module switches of several solar modules can be connected in series, so that the actual state of the several solar modules is summarized and displayed on a remote display. The remote display can advantageously be at the inverter 3 attached or in the housing of the inverter 3 be integrated. The more cables are returned from the display outputs of the solar modules of a photovoltaic system to the display, the more accurately a faulty solar module can be determined. It is advantageous, in particular, to connect all the corresponding display outputs of the module switches of a string or of a substring or of a substring section in series and to feed them back separately for display.

An indication of the condition of the system is possible by monitoring the voltage at the busbars. This is evaluated by the inverter anyway and displayed if necessary. In another embodiment, the voltage at the busbars may also be compared to a threshold value. If, in the operating state, the voltage at the busbars is above the threshold value, a red lamp on the inverter may be switched on. If the voltage on the busbars is below the threshold, a green lamp on the inverter may be on.

However, in the evaluation of the voltage at the busbars there is a risk that they are also affected by system errors such. B. line interruption in a partial destruction of the system, can be very low. It would then erroneously displayed a safe state of the system, although system parts are still under tension. In this respect, the display of the safe state by means of the display elements has significant advantages in terms of safety, because this only takes place when there is actually no voltage.

12 shows a module switch 147 with a relay that has a relay coil 131 and three against each other galvanically isolated normally closed contacts 123 for shorting three strings 115 having. A display element and a shunt resistor are absent in this embodiment. With appropriate dimensioning of the solar cells in the strings 115 and the magnetic circuit can be advantageously used for this purpose a reed relay.

If a plurality of switching elements are required for a module, the control of the contacts with a common magnetic circuit, so a relay with multiple contacts or, as in 13 using modular switches 150 shown, with several single relays 151 . 152 . 153 be achieved. The advantage lies in the easier procurement: there are only a few reed relays with contacts for currents ≥ 1 A as catalog goods, but these are always only individual contacts.

By designing the magnetic circuit with multiple windings, a relay can also with NO contact 164 be operated in self-holding circuit, as with the module switch 160 in 14 is shown. As the module voltage rises above a threshold value, the relay pulls across the inrush current I _E through the switch-on winding 162 and the holding current I _H via the holding winding 163 and stays dressed. Switching off can be done via the control current I _S in the control winding, which is fed in phase opposition to I _E and I _H 161 take place, which compensates for the fields in the magnetic circuit and drop the anchor. The number of turns of the holding winding n _H , turn-on winding n _E and control winding n _S are to be interpreted accordingly: n _H <n _E <n _S (1)

15 shows a module switch 170 in which the actual switching element through a Darlington transistor 173 (BDV65) is formed. In series with the emitter of the Darlington transistor 173 is an emitter resistor 174 (0.1 Ω) switched. The resistance 175 (1.2 kΩ) ensures that the transistor 173 becomes conductive when the make contact 176 a relay in the ground state is open. In the operating state is the NO contact 176 closed and directs the resistance 175 delivered electricity to a potential, due to the resistance 174 still below the emitter potential of the transistor 173 lies, so the transistor 173 becomes non-conductive.

The emitter resistor 174 is generally used to limit the current. When using several parallel-connected transistors instead of transistor 173 can be achieved over several emitter resistors a characteristic shear. With the design of the emitter resistor 174 Furthermore, the voltage required for self-supply of the module switch (about 1-3 V) can be set.

This solution is simple and inexpensive and works over a wide temperature range. It comes with cheap, very well available components. The switching capacity is kept away from the relay. The contact 176 The relay must dissipate only a few mA of control current, even with very powerful solar modules. When using a silicon NPN transistor instead of the Darlington transistor and replacing the resistor 174 a conductor (0 Ω) can be used to achieve module voltages of less than 0.8 V / module in the event of a short circuit. In this way you can achieve harmless string voltages even in systems with very high module numbers in a string. In addition, the power transistor is less warm and it may be possible to dispense with additional cooling.

16 shows a module switch 180 in which the galvanic isolation between control input 111 and switching element by an optocoupler 186 is reached. The switching element consists as in 15 from a Darlington transistor 173 and a series resistor 174 , Between the phototransistor of the opto-coupler 186 and the Darlington transistor 173 is still an inverting driver stage of a pnp transistor 181 (KF517B) and the resistors 182 (18 kΩ) and 183 (82 kΩ) switched. In the ground state, the phototransistor of the opto-coupler provides 186 no power. Therefore, the current switches over the resistor 183 the transistor 181 conducting, in turn, the transistor 173 conductive switches.

17 shows a module switch 190 in which between the phototransistor of the optocoupler 186 and the base of the transistor 181 a Schmitt trigger is installed as a threshold value switch. The components 173 . 174 . 181 . 182 and 186 and their functions have already been linked with 16 explained. The supply voltage of the threshold switch is via the LED 203 (VQA13) and resistance 202 stabilized. The LED of type VQA13 hardly lights up at a current of approx. 2 mA (= 40 V / 20 kΩ).

The npn transistors 197 and 198 (both SC237D) together with the resistors 201 (470 Ω), 192 (8.2 kΩ) and 193 (22 kΩ) form a differential amplifier with an output at the collector of the transistor 198 , an inverted output at the collector of the transistor 197 , a non-inverting input at the base of the transistor 197 and an inverting input at the base of the transistor 198 , The resistance 195 (8.2 kΩ) provides a positive feedback and thus a switching hysteresis, which is typical for a Schmitt trigger. The phototransistor the optocoupler 186 generated together with the resistors 191 (27 kΩ) and 199 (100 kΩ) the input signal for the Schmitt trigger. The resistance 200 (100 kΩ) together with the resistor 195 set the operating point for the transistor 198 firmly. The resistance 194 (4.7 kΩ) limits the current in the base of the transistor 181 , The capacitor 196 (100 nF) suppresses high-frequency noise at the control input and prevents too fast switching of the Schmitt trigger.

Instead of the resistors 201 and 202 Power sources can also be used.

18 shows a module switch 210 , the module switch 190 out 17 similar, but with the phototransistor of the optocoupler 186 the transistor 197 replaced by the Schmitt trigger. The. resistors 212 (4,7 kΩ), 213 (82 Ω), 214 (1 kΩ), 215 (4,7 kΩ), 220 (39 kΩ), 221 (270 Ω) and 222 (4.7 kΩ) in the module switch 210 correspond in their function to the resistors 192 . 193 . 194 . 195 . 200 . 201 respectively. 202 in the module switch 190 , but have slightly different resistance values. About the diodes 224 and 225 becomes the base potential of optocouplers 186 Are defined. The capacitor 223 (4.7 μF) stabilizes in addition to the LED 203 the operating voltage for the Schmitt trigger.

In the embodiments in 16 to 18 . 22 such as 25 The optocouplers can be divided up to a certain extent by fiber optic cables. The LED can then instead of the optocoupler in the control signal source 96 be housed. The control signal is then transmitted to the controls via one or more optical fibers 29 transfer. The control elements then have an optical control input, at which the electric power is typically converted into an electric current by a phototransistor or a photodiode.

19 shows a module switch 230 in which a normally-conducting p-channel MOSFET (metal oxide semiconductor field effect transistor), which is also referred to as a PMOS depletion type, is used as the switching element. When at the control input 111 a sufficiently high AC voltage is applied is via the. transformer 237 and the bridge rectifier 235 the gate of the PMOS 231 opposite the source of the PMOS 231 positively biased, so that at sufficiently high bias the PMOS 231 finally locks, so that the module switch 230 in the operating state. The two capacitors 238 and 236 form together with the corresponding windings of the transformer 237 Resonant circuits. This will create a frequency range for the control input 111 Are defined. Frequency components outside the frequency range are strongly attenuated. The frequency range can be placed in an area of the frequency spectrum where there is usually little interference. Therefore, the range around the line frequency of 50 or 60 Hz is the frequency range for the control input 111 not suitable. In addition, the width of the frequency range and thus the sensitivity to interference can be reduced by a high quality of the resonant circuits. The capacitor 234 smooths out the bridge rectifier 235 delivered pulsating DC voltage. The zener diode 233 and the resistance 232 (18 kΩ) form a voltage divider, with the blocking voltage of the zener diode acting as a threshold voltage that must be exceeded, so that over the resistor 232 a significant source-gate voltage drops. The zener diode 233 is optional.

The amount of voltage between the gate and source, which is to completely block the PMOS 231 is required, is a few volts, often more than 5 V. With the driving of the PMOS via a voltage source, which essentially consists of the transformer 237 , the bridge rectifier 235 and the capacitor 234 is formed, the full modulation range of the MOSFET can be used.

The resistance 239 in drain circuit of the MOSFET 231 ensures a minimum voltage drop at the switching output and can be advantageously replaced by one or more diodes in the flow direction. The resistance 239 is in the 19 . 20 and 21 unnecessary.

20 shows a similar module switch 250 in which, unlike the module switch 230 the galvanic isolation between control input 111 and switching element through the two capacitors 256 and 257 is realized.

21 shows a similar module switch 270 in which the reverse voltage for the PMOS 231 through a DC / DC converter 271 is produced. The DC / DC converter 271 must also provide for the galvanic isolation.

As in 22 can be shown instead of the normally conductive PMOS 231 also a self-locking n-channel MOSFET 281 be used. However, the problem is that the voltage for conducting a typical n-channel MOSFET must be> 5V. It can not be directly out of the string 115 win, because the power turnover would be too high. In addition, then the total voltage in the system in the ground state is too high.

The problem of excessive ground state voltage can be solved by using a DC-DC converter 286 with a low input voltage of <2V on its secondary side provides the gate-source voltage required to fully drive the n-channel MOSFET. The treatment of the control signal then takes place as in the bipolar transistor (see. 15 to 18 ), possibly with level conversion. The Schmitt trigger from the components 186 . 212 . 213 . 215 and 220 . 221 . 223 to 225 was already related to 18 explained. The voltage divider from the resistor 283 (2.2k) and the Zener diode 284 (SZ600) limits the voltage on the primary side of the DC-DC converter 286 , The capacitor 285 (4.7 μF) stabilizes the voltage on the primary side of the DC-DC converter 286 ,

With the DC-DC converter 286 delivered secondary voltage can also be a radio receiver for example for Bluetooth, ZigBee, WLAN, RFID operated. This simplifies the installation because the solar cables do not need to contain signal conductors.

It is known in the prior art that with symmetrical signal transmission signals can be transmitted disturbance-tolerant even with longer transmission paths.

Since at the in 7 presented topology the electrical connections 97 for the control signal over a large area of the photovoltaic generator 92 extend, the coupling of interference signals is correspondingly large. That is why in 23 a topology 300 shown in the two control signal sources 301 and 302 two control loops 305 respectively 306 supply with two out of phase control signals. The solar modules 304 have controls 309 each with a four-pole control input with a two-pole control input 311 and a two-pole control input 312 on. The currents through the two control inputs 311 and 312 be added. In that the positive input of the control input 311 in 23 below and the positive input of the control input 312 in 23 is above, the antiphase control signals are added in magnitude and in-phase noise in the two control loops 305 and 306 subtracted from each other, so that cancel in-phase interference.

As a rule, the lines of the two control loops 305 and 306 twisted so that the area enclosed by both control loops is as similar and equal as possible, so that alternating fields actually couple as equally as possible in both control loops.

In the 23 illustrated topology 300 can be simplified by, for example, the two lower control inputs 313 of in 23 at the bottom of the illustrated control 309 be connected conductively and a single control signal source is used, which over the in 23 above shown lines of the loops 305 and 306 in the 23 At the top of the picture are entrances 314 fed. In the 23 shown below lines of the loops 305 and 306 can be omitted. This results in a single, n-shaped loop, which includes only a very small area and thus collects relatively low interference, with twisted lines individual areas provide positive and negative contributions that largely compensate.

24 shows a module switch 320 with a control input 312 and a control input 311 , The addition of the two currents through the two control inputs 312 and 311 takes place in transformer 321 , The important thing is that the transformer 321 has two galvanically isolated primary coils. Although the transformer 321 Also has two galvanically isolated coils on the secondary side, a secondary coil would be sufficient. The capacitors 322 and 323 together with their primary winding form oscillating circuits. The further circuit with the components 115 . 231 to 236 such as 239 was already referring to 19 described.

25 shows a module switch 340 , which also has two control inputs 311 and 312 having. The control inputs 311 and 312 are with a light emitting diode of optocouplers 341 respectively 342 (MB104C). These LEDs are through the diodes 343 respectively 344 (SAY17) protected against reverse polarity. The two phototransistors of the two optocouplers 341 and 342 are connected in series. This achieves an AND operation instead of an addition between the two control signals. Only if both control signals at the control inputs 311 and 312 abut, both phototransistors are conductive. On the other hand deliver the two control signal sources 301 and 302 no electricity, but are in the control loops 305 and 306 strong, in-phase noise coupled, is at best one of the phototransistors conductive, so that the module switch remains in harmless ground state.

The other components 115 . 173 . 174 . 181 . 182 . 191 to 195 such as 197 to 203 were already referring to 17 explained.

The capacitor 345 corresponds to 17 the capacitor 196 , however, has been chosen ten times as large, namely 1 μF. If the two control signal sources 301 and 302 provide a control current and simultaneously strong in-phase noise in the two control loops 305 under 306 can be coupled, it may happen that one of the two phototransistors becomes temporarily non-conductive. On the other hand, it must be prevented that the transistor 173 Too often off and on, because when switching off and on particularly high power in the transistor 173 is implemented, the low pass from the capacitor 345 and the resistance 199 provided with a larger time constant of 100 ms. As a result, even disturbances from the railway network with a frequency of 16 2/3 Hz and certainly all high-frequency disturbances, for example, from the power grid are significantly attenuated.

Various combinations of control and switch element are conceivable. Specified circuit variants are only examples. The module switches or parts thereof can also be designed as an integrated circuit.

In the case of a multi-channel structure for multi-string modules active components of the same function can also be integrated in a common housing such. B. transistor arrays, multiple optocouplers, relays with multiple windings and / or switching contacts. When using module switches in several individual strings within a module, the module switches are galvanically isolated from each other.

The resistors 133 . 174 . 239 and 282 serve to maintain a minimum voltage drop for self-voltage supply and can also be outside the junction box, because the converted by the resistance power loss can be quite large. These highly stressed resistors can advantageously be accommodated on the module surface, for example by vapor deposition

26 shows a solar cable according to the invention 360 which is particularly good for the connection between the individual solar modules 94 as well as the solar modules 94 and the busbars 8th and 9 is suitable (see 7 ). The solar cable 360 has a total of six energy ladders 361 on, with each energy ladder its own vein cladding 362 having. Each of the solar modules 94 may therefore have a maximum of six substrings. Furthermore, the solar cable has a signal conductor 363 for the serial connection of the control inputs of the controls 29 on. The signal conductor 363 also has its own wire wrap 364 and has a smaller cross section than the power conductors 361 , The veins shrouds 362 and 364 are in a cable sheath 365 embedded. The cross-section of the cable sheath 365 is circular, because you can seal a circular cross section particularly well against rainwater.

27 shows another solar cable according to the invention 370 with three energy directors 371 and four signal conductors 373 , Both the energy ladder 371 as well as the signal conductors 373 are of veins 372 respectively 374 surround. The cable sheath 375 again has a circular cross-section. This solar cable is suitable for solar modules with up to three partial strings, symmetrical control signals (cf. 23 ) and two display outputs (cf. 11 ).

28 shows a further inventive solar module 400 , As with conventional solar modules, there is a pane of glass on the side facing the sun 401 , Underneath is a continuous EVA foil 402 , Underneath are the solar cells 403 in a cut EVA film 404 , Underneath is a backside insulation 405 , which consists for example of polyvinyl fluoride (Tedlar). Below is a metal rear wall according to the invention 406 , in addition to cooling fins 407 can have. The metal back wall 406 may for example consist of aluminum. A frame 408 Holds the different layers of the solar module 400 together. The frame 408 usually consists of aluminum.

Should be in the solar module 400 arc, it is unlikely that molten metal drips through the metal back wall, for example, on underlying roof tiles, roof battens, rafters or grass and causes a fire. The cooling fins 407 improve by cooling the solar cells 403 the efficiency of the solar cells 403 , Instead of cooling fins 407 came the solar module 400 can also be installed in a solar thermal collector and cooled by the liquid in the solar collector.

The invention has been explained in detail above with reference to preferred embodiments. However, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the spirit of the invention. Therefore, the scope of protection is defined by the following claims and their equivalents.

LIST OF REFERENCE NUMBERS

1

Photovoltaic system

2

Photovoltaic Generator

3

inverter

4

solar Panels

5

string

6

series diode

7

fuse

8, 9

bus

11

solar cells

14

solar module

15

substring

17

junction box

18

Bypass diode

21

solar cells

22

solar cell array

23

switching element

24

solar module

25

substring

26

series diodes

27

Module Wall Outlet

28

Bypass diode

29

control

30

plus connection

31

negative connection

32

taps

33

Plus solar cables

34, 35

Minus Solar Cable

36

electrical conductor

38

chamber

41

curve

42, 43, 44

characteristics

44

solar module

45

Point of maximum power

46

stable operating point

51

curve

55

Point of maximum power,

56

stable operating point

63

switching element

64

solar module

65

Circuit symbol for solar modules

74

solar module

75

substring

81

Photovoltaic system

82

Photovoltaic Generator

84

solar module

86

series diode

87

fuse

88, 89

multipolar contact point

91

Photovoltaic system

92

Photovoltaic Generator

94

solar module

95

Emergency switch

96

Control signal source

97

electrical connections

98, 99

management

101

Photovoltaic system

102

Photovoltaic Generator

108

busbars

110

general module switch

111

control input

112

Signal receiving circuit

113

switching element

114

driver stage

115

string

116

switching output

117

display element

120

module switch

122

control

123

Normally Closed

127

display element

131

relay coil

132

diode

133

shunt resistor

134

LED

136

Zener diode

137

series resistance

138

LED

140

module switch

141, 142

optocoupler

143, 144

display output

147

module switch

150

module switch

151, 152, 153

Single relay

161

control winding

162

Einschaltwicklung

164

NO contact

170

module switch

173

Darlington

174

emitter resistor

175

resistance

180

module switch

181

PNP transistor

182, 183

resistance

186

optocoupler

190

module switch

191, 192, 193, 194, 195, 199, 200, 201, 202

resistance

197, 198

transistor

203

LED

210

module switch

212, 213, 214, 215, 220, 221, 222

resistance

223

capacitor

224, 225

diodes

230

module switch

231

PMOS

232, 239

resistance

233

Zener diode

234, 235, 236, 238, 256, 257

capacitor

235

Bridge rectifier

237

transformer

250, 270

module switch

271

DC / DC converter

286

DC-DC converter

282, 283

resistance

284

Zener diode

285

capacitor

300

topology

301, 302

Control signal sources

304

solar module

305, 306

control loops

309

control

311, 312, 313, 314

control input

320

module switch

321

transformer

322, 323

capacitors

340

module switch

341, 342

optocoupler

343, 344

diodes

345

capacitor

360

solar cable

361

energy conductor

362, 364

Inner covering

363

signal conductor

365

cable sheath

370

solar cable

371

energy conductor

373

signal conductor

372, 374

Inner covering

375

cable sheath

400

solar module

401

pane

402

EVA film

403

solar cells

404

EVA film

405

Back insulation

406

metal back wall

407

cooling fins

408

frame

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

• US 2006/0171085 A1 [0007]
• US 6259996 B1 [0007]
• US 6633824 B2 [0007]
• WO 95/25374 A1 [0007]
• EP 1709504 B1 [0007]
• WO 2004/010556 A3 [0008]
• US 2009/0114263 A1 [0010, 0068]

Cited non-patent literature

• Elektroprofi 2/2008, pp. 43-45 [0006]
• I. Müller: "Arc Fault Protection in the DC Part of Photovoltaic Systems", Wissenschaftsverlag Ilmenau, 2002, ISBN: 3-936404-02-X [0007]
• DIN VDE 0100-712 [0009]

Claims (20)

Solar module ( 24 . 64 . 74 . 84 . 94 ) with: at least two strings ( 25 . 65 . 75 ), each string containing a plurality of solar cells ( 21 ), which are connected in series, characterized in that each string is galvanically isolated from the other strings. Solar module according to claim 1, characterized in that the solar module further comprises a module junction box ( 27 ), wherein there are two contact points in the module junction box for each string. Solar module in particular according to claim 1, characterized in that the solar module at least one string ( 25 . 65 . 75 ), wherein the solar module is a series diode ( 26 ), for example a Schottky diode, which is connected in series with the solar cells of the string so that the voltage supplied by the solar cells poles the series diode in the direction of flow. Solar module ( 24 . 64 . 74 . 84 . 94 ) according to one of the preceding claims, characterized in that for the positive connection of the string a chamber ( 69 ) in the module junction box ( 27 ) and for the minus connection of the string another chamber ( 69 ) in the module junction box ( 27 ) is provided. Solar module in particular according to one of the preceding claims, characterized in that the rear wall ( 406 ) of the solar module ( 400 ) is made of a metallic material, such as aluminum. Solar module according to claim 5, characterized in that the rear wall of the solar module with a profile ( 407 ) is provided. Module switch for a string of a solar module, wherein the string is a plurality of solar cells ( 21 ) connected in series, comprising: a control input ( 111 ); and a switching output ( 116 ) with two electrical connections, wherein the two electrical connections are high-impedance or electrically isolated, if at the control input ( 111 ) a signal is present above a threshold value and the two electrical connections of the switching output ( 116 ) are connected to each other at low resistance, when at the control input ( 111 ) a signal below the threshold is applied. Modular switch according to claim 7, characterized in that the control input ( 111 ) has two electrical connections and the module switch further comprises an antenna which is connected to the two electrical terminals of the control input ( 111 ) connected is. Modular switch according to claim 7, characterized in that the control input ( 111 ) and the switching output ( 116 ) are electrically isolated from each other ( 131 . 123 ; 151 . 152 . 153 ; 161 . 162 . 163 . 164 ; 176 ; 186 ; 237 ; 256 . 257 ; 271 ) are. Module switch according to one of claims 7 to 9, characterized in that the module switch further comprises one or more display elements ( 134 . 138 ), which indicate the high-resistance and / or low-resistance state. Module switch according to one of claims 7 to 10, characterized in that the module switch when switching from low-impedance to high-resistance state and vice versa has a hysteresis. Module switch according to one of claims 7 to 11, characterized in that the module switch two control inputs ( 311 . 312 ) for 2 out of phase control signals. Modular switch according to one of claims 7 to 12, characterized in that the switching output ( 116 ) has two contact points on each of the two electrical connections. Solar module, in particular according to one of claims 1 to 6, wherein the solar module at least one string ( 25 . 65 . 75 ) comprising a plurality of solar cells ( 21 connected in series, characterized by: a module switch according to one of claims 7 to 13, wherein the switching output ( 116 ) of the module switch is connected in parallel to the string. Solar cable ( 33 . 34 . 35 ), characterized in that the solar cable has a plurality of mutually insulated electrical conductors, wherein the wire sheath of the electrical conductor consists of an arc-inhibiting material. Solar cable according to claim 15, characterized in that one of the plurality of electrical conductors has a smaller cross section than the one or more other electrical conductors. Busbar ( 8th . 9 ) for solar systems, characterized in that the busbar multi-pole contact points ( 88 . 89 ) for solar cable ( 33 . 34 . 35 ) having a plurality of electrical conductors. A machine ( 96 ) for generating a control signal for solar modules ( 94 ) according to claim 14, whereby the solar modules ( 94 ) Part of a photovoltaic system ( 91 ), comprising: an output for outputting a signal to the module switches of the solar modules; an input for connection to busbars ( 8th . 9 ) of the photovoltaic system, whereby the device is intended and suitable, from the low voltage at the 8th . 9 ), when the module switches of the solar modules are in the low-resistance state, to generate a signal at the output, which switches the module switch in the high-resistance state, and the device by the higher voltage at the busbars, when the module switches are in the high-resistance state, not gets destroyed. Device according to claim 18, characterized in that the device has a switch ( 95 ) with two positions, wherein the device is intended and suitable to generate in the first position of the switch, a signal at the output, which switches the module switches of the solar modules in the high - resistance state, when the module switches are in the low - impedance state or the module switches in high-resistance state holds when the module switch in the high-impedance state and in the second position of the switch generates no signal at the output. Device according to one of claims 18 or 19, characterized in that the device is an inverter ( 3 ) or charge controller.

Images