Intrinsic safety energy transfer unit for supplying electrical appliances with increased power

Abstract

Intrinsic safe energy transfer unit and energy transfer system for powering electrical appliances within an explosion protected area. Power is transferred from an energy source with multiple electrically separated individual sources by means of a line connection implemented as a multiple line with multiple electrically separated and individually shielded conductor pairs. At the end of the multiple line, a collector device is provided in an ignition protected enclosure. The collector device has decoupling means for the electrically separated conductor pairs and has a combiner circuit. The combiner circuit combines the electrical power transferred by the electrically separated conductor pairs respectively into a total power, wherein the total power is output at an output of the collector device to an electrical appliance. By spreading to multiple conductor pairs, a scalable, increased total power can be transferred intrinsically safe and can be transferred using common intrinsic safe conductor pairs according to standards. Thus, with less effort, an electrical appliance is supplied with an extralarge power intrinsically safe.

Description

TECHNICAL FIELD

[0001] The present application relates to an intrinsically safe energy transmission unit for providing an electrical appliance with increased power, which is suitable for use in explosion-hazardous areas. The energy transmission unit comprises a line connection and is configured to intrinsically safely transmit electrical power from an energy source to the electrical appliance via the line connection. BACKGROUND

[0002] In special application cases, electrical appliances are used in explosion-hazardous areas, for example in areas in which combustible gases, dust or other explosive substances can be present. In order to avoid explosion hazards, neither the electrical appliances nor their energy supply devices are allowed to form ignition sources that can cause explosions. For this purpose, the devices installed in or located in explosion-hazardous areas must be constructed according to a specific ignition protection type.

[0003] The explosion protection rules defined in the relevant national and international standards and guidelines specify different ignition protection types, according to which electrical devices are classified in the ignition protection types according to the explosion protection respectively applicable to the electrical devices. In many cases, it is advantageous to apply the "intrinsically safe" ignition protection type (abbreviation: symbol "Ex-i"). In the case of this ignition protection type, the voltage, current and power are limited in such a way that it is not possible to generate ignition sparks or dangerous heat generation. Here, the limits are chosen in such a way that the minimum energy and ignition temperature of an explosive mixture are not reached. Intrinsically safe electrical operating devices only contain circuits that meet the requirements for intrinsically safe circuits. For intrinsically safe circuits, only circuits with low power are considered. Here, the voltage, current and power are limited in such a way that it is not possible to form combustible sparks or dangerous heat generation. There are two technical implementations for this case, namely "Ex ia" and "Ex ib". "Ex ia" has a particularly high safety, "Ex ib" has a high safety. This technical implementation is described, for example, in the IEC 60079-11 standard.

[0004] Due to the limits relating to voltage, current and, correspondingly, also to power, it has proven to be difficult to supply sensors, in particular by means of long lines, with power, in particular when the power required by the measuring sensors exceeds the power allowed by safety technology. In the case of the "Ex ia" ignition protection type, the power is usually limited in practice to values in the range of approximately 2 watts, depending on the respective specific values of the current, voltage, line unit length parameter (Leitungsbelägen) and other device parameters.

[0005] If the power required for powering an electrical appliance exceeds the permissible power specified in accordance with the IEC 60079-11 standard in the case of a given voltage and current state (Stromlage), the application of the method mentioned in the IEC 60079-39 standard has provided a remedy for some time. This method provides for detecting a short circuit or interruption of the line and then interrupting the energy input before an explosion can occur. This method requires a relatively large outlay. Due to the electronic current limitation, auxiliary circuit and decoupling network required for this, only a lower ignition protection type "Ex ib" can be achieved. For higher ignition protection types "Ex ia" this is generally not a solution. SUMMARY

[0006] There is a need for an intrinsically safe supply device with which an electrical appliance having a higher power requirement than the conventional intrinsically safe transmissible power requirement can be supplied with power for a longer period of time.

[0007] On the basis of this, the invention is based on the task of increasing the intrinsically safe energy transmission of the type mentioned at the outset in terms of transmissible power.

[0008] The solution according to the invention is based on the features of the independent claim. Advantageous extensions are the subject matter of the dependent claims.

[0009] In the case of an intrinsically safe energy transmission unit, which is suitable for an explosion-protected area for powering an electrical appliance, the energy transmission unit comprises a line connection and is configured to intrinsically safely transmit electrical power from an energy source having a plurality of electrically separated individual sources (Einzelquellen) to the electrical appliance via the line connection, it is provided according to the invention that the line connection is embodied as a multiple line having a plurality of electrically separated and individually shielded conductor pairs, a conductor pair for connecting to the individual sources respectively, and at the end of the multiple line on the appliance side a collector device is provided, which is embodied in an explosion-protected manner in an ignition-protected envelope and has a connection end for the electrically separated conductor pair respectively and a combiner circuit, wherein the connection end is equipped in the collector device with a decoupling device, which prevents a reaction on the connected conductor pair, and the combiner circuit is configured to combine (zusammenführen) the electrical power transmitted by the electrically separated conductor pairs at the connection end respectively into a total power, wherein the total power is output at the output of the collector device to the electrical appliance.

[0010] The invention is based on the idea of supplying an electrical appliance with an übergroß power from a suitable energy source still intrinsically safe, in such a way that the power transmission takes place via a plurality of electrically separated and individually shielded conductor pairs, wherein the individual Leistungen transmitted via the respective conductor pair are combined after the decoupling device into a total power for output to the electrical appliance. Here, "übergroß" means that there is a higher power than can be transmitted intrinsically safe via a single line. The limit value is the permissible power specified according to IEC 60079-11 in the given voltage and current state. Here, the individual conductor pairs and their supply by the energy source, in particular by a single energy source, are intrinsically safe in each case in a manner known per se, but are insufficient in terms of power. By spreading the power to be transmitted to a plurality of conductor pairs, an increased power, which is itself arbitrarily scalable, can be transmitted intrinsically safe, and common standard-compliant conductor pairs can be used for the intrinsically safe transmission, for example according to IEC 60079-25. It is thus made possible to supply an electrical appliance with an übergroß power intrinsically safe with less outlay. This applies in particular in the case where the individual conductor pairs are connected to a corresponding plurality of electrically separated individual sources of the energy source, wherein the individual sources are current- and / or voltage-limited, in particular power-limited, according to the IEC 60079-11 standard. It is thus possible, thanks to the invention, to create a line connection which supplies an electrical appliance with an übergroß power intrinsically safe, in particular in compliance with the requirements of the IEC 60079-25 standard.

[0011] Within the scope of the invention, a power limitation is to be understood as a limitation of the current and voltage. Such a limitation results from the specification's predefined values and inevitably leads to a corresponding limitation of the power. However, the invention in principle allows a particularly large total power to be present while complying with the specification's predefined values. According to the invention, the respective limitation of the power is thus not derived from the safety-technical aspect, but for example from properties or functions of the load, in particular of the electrical appliance, which are independent of the safety-technical aspect.

[0012] A particular advantage of the invention is that a higher power transmission is comparatively less outlay-intensive and in particular does not require complex electronic devices. This is particularly effective in comparison with the method specified according to the IEC 60079-39 standard mentioned at the beginning. A further advantage provided by the invention is that a higher degree of reliability can be achieved due to the less outlay, in particular due to the less complexity of the electronic devices.

[0013] Furthermore, due to the particularly high degree of safety which can be achieved with the application, even the "Ex ia" protection type can be met, and in particular the "Ex ia" protection type can be met in the case of circuiting of the individual conductor pairs by passive components, for example resistors.

[0014] Even in the event of faults, for example in the event of damage to the line connection as a result of mechanical action or insulation faults, the energy transmission via the plurality of electrically separated conductor pairs according to the application remains intrinsically safe. For example, if one line is damaged as a result of a cut, firstly one conductor pair is cut, then the next conductor pair is cut, and so on. Here, the cutting tool firstly cuts the shielding, then cuts the first conductor of the conductor pair, next cuts the second conductor of the conductor pair, and finally cuts the remaining part of the shielding, wherein in the worst case, assuming a conductive cut, firstly the shielding is connected to the first conductor of the conductor pair and next this first conductor is connected to the second conductor of the conductor pair. Since in the case of intrinsically safe energy transmission the individual conductor pairs in principle only transmit a small, safety-technically harmless amount of power, in the event of a short circuit only a safety-technically harmless through current arises. The sequence is then repeated for the other conductor pairs. It is crucial that the individual conductor pairs are cut step by step when cutting, so that only the current from a single source is interrupted at the same time, but never the sum of the currents from a plurality of single sources. Since the cut is safety-technically harmless for the single source itself, the stepwise cutting of the line connection according to the application does not lead to an ignition. Due to the shielding used, this cutting situation is correspondingly safe in all conceivable situations. If a breakage occurs, this situation can be more critical. Here, the worst case is that n-1 return conductors are interrupted first of all in n conductor pairs, wherein the sources are electrically connected to one another, for example by a common ground on the source side. In the case of a simultaneous interruption, the current of all n conductor pairs then flows through the only remaining return conductor. If this only remaining return conductor is then also interrupted, n times the current is separated off, which can then lead to an ignition spark. This can be avoided by the electrical separation of the single sources, so that in this respect a safety is achieved. Finally, the case of an insulation fault is also to be considered. In principle, the insulation of the line connection can fail for various reasons, for example as a result of physical overload, in particular because of pressure, temperature and / or UV radiation, or as a result of decomposition due to chemical influences. Here, in the absence of insulation a short circuit is always only formed between the two conductors of a conductor pair inside the shielding mesh as a result of the shielding. The short-circuit current is therefore limited to the intrinsically safe degree of the current flowing through one conductor pair. A dangerous increase in current is therefore not possible.

[0015] "intrinsically safe" can be understood as an electrical circuit in which neither the thermal effects nor the sparks occurring under the test conditions specified in the standard can ignite an explosive atmosphere of the specific standardized components. Thus, in the case of the ignition protection type "intrinsically safe", the power is always limited and, precisely, such that in the event of a short circuit due to the occurrence of a spark, only a release of energy which is not dangerous from a safety-technical point of view is possible. This is a measure of the secondary explosion protection which the term "explosion protection" relates to. These definitions are professional and can be found in the relevant standards, for example in the IEC 60079 standard family, in particular in the standard parts -11, -14, -25.

[0016] "not susceptible to interference" is a professional term which is used in the relevant standards on intrinsic safety to evaluate components and component groups. Thus, for example, Zener diodes and other semiconductor elements for limiting the voltage are generally considered to be susceptible to interference, whereas, in contrast, layer resistances or line resistances for limiting the current are considered to be components which are not susceptible to interference under specific specification preconditions.

[0017] However, it is expedient that not only the energy transfer according to the application and in particular the energy source of the energy transfer is implemented to be intrinsically safe, but also the electrical appliance itself is implemented to be explosion-protected according to the standardized ignition protection type, preferably according to Ex ia or Ex ib, to be intrinsically safe. It is particularly preferred that a chain up to and including the electrical appliance can be formed to be intrinsically safe with regard to the supply power and the energy consumption.

[0018] Advantageously, the collector device and / or the combiner circuit is potted and / or arranged in a pressure-resistant housing. By the potting or the arrangement in a pressure-resistant housing, a particularly good protection is achieved for the critical area in which the power flowing through the plurality of conductor pairs is combined together. Due to the potting, an explosive gas cannot reach the circuit which guides the entire power at all, otherwise the pressure-resistant housing would act as a protective containment in the event of a fault.

[0019] Preferably, the decoupling device has redundantly implemented decoupling elements. The redundancy ensures a higher operational safety, since in the event of a failure of one of the decoupling elements, the decoupling function can also be maintained. In order to further simplify, the decoupling elements are implemented as preferably passive current valves, whereby the decoupling elements can have a higher reliability than active elements. Here, the current valves are connected in a non-susceptible series circuit in their respective decoupling device. Thus, a failsafe behavior can be achieved in the event of a failure of one or more current valves: if a current valve occurs a severe short circuit otherwise, the desired function is still achieved in the case of a series circuit.

[0020] The combiner circuit is suitably configured to combine the currents transmitted by the conductor pairs and, in particular, is preferably configured as a parallel circuit. Thus, the individual currents (Einzelstrom) transmitted by the individual conductor pairs can be combined into a total current in a technically little outlay and thus reliable manner, since only a small number of components is required. Alternatively, however, the combiner circuit can also be implemented, preferably as a series circuit, such that the individual voltages (Einzelspannung) of the respective conductor pairs are connected (verketten) to form a higher total voltage. Thus, a higher supply voltage can be supplied to the electrical appliance in an equally simple and ingenious manner.

[0021] Advantageously, a current limitation and / or a power limitation is provided for the conductor pairs. In general, intrinsically safe energy sources have limitations, either in terms of current, voltage and / or power. However, it is still advantageous, particularly in terms of redundancy or broader usability, for example in the case of use with other, not correspondingly limited energy sources, for the energy transmission unit to have its own current limitation and / or power limitation and, in particular, to have its own current limitation and / or power limitation in the line connection and / or at the beginning of the line connection, in the collector device and / or on the energy source side of the line connection. A particularly simple and suitable implementation of the current limitation can be achieved by means of a resistor. In order to also achieve a power limitation in terms of load characteristics or load functions that are independent of safety technology, the resistor can be used in combination with other actuators (Stellglied). Thus, whether as a starting portion of the line pair or connected upstream, a resistor can be provided at the beginning of the line pair in order to obtain the desired limitation via the entire extension of the line pair from the outset. However, additionally or alternatively, it can also be provided that the current limitation and / or the power limitation, for example the resistor, is arranged in the collector device or implemented as integrated into the energy source. Thus, the line connection and its conductor pairs can remain free of additional limiting components, which simplifies the structural implementation. Suitably, the power limitation of the conductor pairs is dimensioned (bemessen) in the range between 1.5 and 2.5 watts.

[0022] Advantageously, the electrical appliance is implemented as a field device, in particular as an active sensor, a telemetry device, a communication device, an actuator and / or a regulator of a process engineering facility. Furthermore, the electrical appliance can have its own battery, either for the purpose of increasing reliability or as an additional power supply.

[0023] Preferably, the collector device is equipped with a voltage regulator which is configured to adjust and / or limit the voltage applied at the connection terminals of the conductor pairs to a predetermined value, wherein the voltage regulator is preferably implemented intrinsically safe, in particular in a shunt topology. Thus, an adjusted output voltage of the collector device can be achieved. This can be used advantageously not only for powering electrical appliances which desire a stabilized supply voltage, but also for charging a battery of the electrical appliance, for example. Suitably, the voltage regulator itself is also implemented intrinsically safe. In particular, in the case of an implementation of the collector device under potting, the voltage regulator is also potted together. In comparison with a common longitudinal regulator, the implementation in a shunt topology makes an implementation according to "Ex ia" intrinsically safe possible. Furthermore, by means of the shunt regulator, the voltage of the battery can be limited with the line resistance and internal resistance of the energy source. In this case, advantageously, the actuator of the voltage regulator is arranged on the line side in front of the decoupling device. This offers the advantage that the actuator "sees" only the power from its own source and cannot "see" the power from the battery which is arranged in the electrical appliance, if necessary.

[0024] It is particularly advantageous if the maximum battery voltage limitation of the battery is to be achieved by means of the shunt regulator. For this purpose, a limiter circuit is suitably provided which is configured to end or at least temporarily interrupt the charging of the battery when a predefined threshold value, for example the maximum voltage of the battery, is reached.

[0025] Furthermore, in order to protect the battery, a release circuit can advantageously be provided in the electrical appliance which is configured to execute the charging process of the battery only when the battery has a certain predetermined minimum voltage.

[0026] Suitably, it is also provided that each of these connection terminals is assigned its own voltage regulator. This makes it possible for the loss power to be distributed to the individual voltage regulators, thus in the case of n voltage regulators at n conductor pairs in n small parts. Furthermore, an interaction of different connection terminals is avoided. In addition, the arrangement of the voltage regulators in the collector device has the advantage that the loss power of the voltage regulators occurs in the collector device and not in the electrical appliance which can be more sensitive to heat.

[0027] Advantageously, the ground lines of the conductor pairs are insulated in the line connection and are only merged in the collector device, preferably in a spark-protected encapsulation, or are passed through the collector device in order to be merged in the electrical appliance. The ground lines are preferably merged into a ground potential ("GND") which is not susceptible to interference. The interconnection of the individual conductor pairs (Zusammenschaltung) is here carried out completely in the combiner circuit of the collector device or even in the electrical appliance to be powered.

[0028] Suitably, the conductor pairs are arranged in a common sheathing (Ummantelung). This simplifies the guided and protected arrangement of the line connection. Furthermore, the line connection is preferably equipped with a shield, wherein the shield is preferably grounded on one side, in particular on the source side. By means of a shield which is grounded on one side, interfering electromagnetic influences can be attenuated, and a potentially dangerous potential drag (Potentialverschleppung) is excluded by means of the shield.

[0029] Furthermore, a potential monitor (Potentialwächter) can optionally be provided on the conductor connection. The potential monitor is suitably configured to monitor the voltage of the individual power supply circuits. In addition, an insulation monitor (Isolationswächter) can optionally be provided, which is configured to detect short circuits in a conductor pair and / or between conductor pairs and to limit the passage current through these conductor pairs in the event of a short circuit being identified. An effective monitoring of the operational safety of the energy transmission unit can be achieved by means of the potential monitor and / or the insulation monitor.

[0030] The invention also extends to an intrinsically safe energy supply system which is suitable for powering electrical appliances in an explosion-protected area, comprising an energy source and an energy transmission unit as described above. For further details of the energy transmission unit, reference is made to the above description.

[0031] With regard to the energy source, it should be noted that the energy source comprises a plurality of individual sources, wherein each individual source is assigned to one of the conductor pairs and is electrically separated from the other individual sources. The energy source and / or its individual sources are preferably current-limited and / or voltage-limited and for this purpose are suitably provided with an output resistance. It is thus possible in a suitable manner to limit the current and voltage in a manner desired for intrinsic safety to values which are not dangerous in terms of safety technology and to limit the power which can be transmitted for each individual conductor pair accordingly. For applications which only need to be protected in accordance with "Ex ib", it is also possible not to carry out a series resistance limitation but to redundantly electronically limit the current to the active components, for example by means of a transistor circuit.

[0032] With regard to the electrical appliance, it should be noted that the collector device can optionally be integrated into the electrical appliance or vice versa, wherein the electrical appliance is preferably a field device, in particular an active sensor, actuator or regulator of a process technology installation. In particular in the case of electrical appliances with high power requirements, the merging takes place only at the collector device by means of the collector device in order to avoid unnecessarily long transmission paths with combined currents and / or combined voltages.

[0033] Preferably, the electrical appliance has a battery, which preferably has an integrated charging regulator for the battery, wherein the charging regulator is further preferably configured as a voltage-controlled (spannungsgeführt). The application can thus be used for charging the battery of the electrical appliance or also for clamping (Klemmung) the battery voltage. Here, a limiter circuit is preferably also provided, which is configured to end the charging of the battery when a predefined threshold value, in particular a maximum voltage, is reached. BRIEF DESCRIPTION OF DRAWINGS

[0034] The application is described below on the basis of advantageous embodiment examples.

[0035] Figure 1 A schematic diagram of an intrinsically safe energy supply system is shown;

[0036] Figure 2 An equivalent circuit diagram of Figure 1 is shown;

[0037] Figure 3 A first embodiment with current interconnection is shown;

[0038] Figure 4 A second embodiment with voltage interconnection is shown;

[0039] Figure 5 A shunt regulator for an energy transfer unit is shown;

[0040] Figure 6 An energy source with advantageously embodied transformer is shown;

[0041] Figure 7 An energy transfer unit according to an implementation variant for powering different electrical appliances is shown. DETAILED DESCRIPTION

[0042] In Figure 1A schematic diagram showing an example of an intrinsically safe energy transmission system 10 according to the application is shown in Fig. 1. As main components, the energy transmission system comprises an intrinsically safe energy transmission unit 1 for powering an electrical appliance 8 as load, wherein the required power is fed from an energy source 9 into the energy transmission unit 1.

[0043] The energy transmission unit 1 comprises a line connection 2 with a multiple line 3 having a plurality of conductor pairs 31-34. In Figure 1 Fig. 1 four conductor pairs are shown by way of example, but there can also be 2, 3 or 5 and more conductor pairs. The conductor pairs are each equipped with their own shield 35 and arranged in a common envelope 30. In this embodiment, the shield 35 is grounded 36 on one side and, precisely, on the source side, that is to say on the side of the energy source 9.

[0044] The line connection 2 has a plurality of input connection terminals 21, 22, 23, 24, wherein the number of input connection terminals is the same as the number of conductor pairs 31, 32, 33, 34. The energy source 9 has a plurality of electrically separated individual sources 91, 92, 93, 94, wherein one of these energy sources 91-94 is assigned to each of the connection terminals 21-24. At the beginning of each of the conductor pairs 31-34, a limiting device 20 is shown, which can be implemented as a current or voltage limiting device (in the simplest case as a passive resistor). The limiting device limits the current and / or the voltage in each of the conductor pairs 31-34 to an intrinsically safe extent. How great this extent is in each case is derived from the relevant standards and determined accordingly by the person skilled in the art. Typically, a single power for each of the conductor pairs 31-34 is thus obtained which is less than 3 W, mostly in the range of 1.5 W to 2.5 W.

[0045] The other end of the multiple line 3 is connected to a collector device 4. To this end, the collector device 4 has a plurality of connection terminals 41, 42, 43, 44, to which the ends of the conductor pairs 31, 32, 33, 34 are connected. The collector device 4 combines the individual powers transmitted via the individual conductor pairs 31-34 to a total power. Due to the higher currents / voltages occurring in the process, the collector device 4 is arranged in a pressure-resistant housing 5 for protection. Alternatively or additionally, the collector device 5 is arranged under a potting 50 (see Figures 3 to 5 ). The total power thus formed is provided at an output 48 of the collector device 4, wherein the electrical appliance 8 to be powered is connected as a load to the output.

[0046] In Figure 2The equivalent circuit diagram is shown. Energy source 9 can be seen in the left area of ​​the image, its output resistance symbolized by impedance 99. Impedance 99 limits the maximum current that can be extracted from source 91, and thus indirectly also limits the power that can be extracted. Next connected is line connection 2, with line resistance 37, line capacitance 37', and line inductance 37'' arranged in conductor pairs. Figure 2 The collector device 4 is not shown because it is electrically transparent. Finally, the electrical appliance 8 is formed as a load.

[0047] exist Figure 3 A first embodiment is shown. This first embodiment is configured such that the currents transmitted in the respective conductor pairs 31-34 are interconnected. For this purpose, the collector device 4 is equipped with a combiner circuit 47. The terminals 41-44 are connected to the combiner circuit 47 via decoupling devices 45. For redundancy, each of these decoupling devices 45 includes a plurality of decoupling elements 46, 46', 46'', which, in the illustrated embodiment, are implemented as three diodes connected in series. The decoupling elements act as current valves, conducting the currents transmitted by the respective conductor pairs 31-34 to the combiner circuit 47. In the illustrated embodiment, the combiner circuit is implemented such that it connects the respective currents in parallel and sums these currents into a total current. The total current thus formed can be output to a load formed by an electrical appliance 8, which, in this embodiment, is integrated with the collector device 4 and mounted under a common potting compound 50.

[0048] In this embodiment, with Figure 1 The current limiting device 20 is implemented in a simplified form, that is, the current limiting device 20 is implemented as a limiting resistor 39 connected downstream of a single source 91-94 at the beginning of the line connection 2.

[0049] exist Figure 4 A second alternative implementation is shown. The second alternative implementation is essentially the same as... Figure 3 The embodiments shown are consistent, with the same or similar elements having the same reference numerals. The difference in the second alternative embodiment is essentially the use of a different combiner circuit 49. This combiner circuit is configured to connect the individual conductor pairs 31-34 in series and thus perform voltage accumulation. The resulting total voltage is then output to the electrical appliance 8 as a load.

[0050] exist Figure 5In the shown embodiment variant, a shunt regulator 6 is additionally provided for the energy transmission unit. The shunt regulator 6 is exemplarily shown at the connection end 44 of the conductor pair 34, it is expedient to provide a shunt regulator also for the other connection ends. The shunt regulator 6 is likewise arranged in the potting 50. The shunt regulator 6 is configured to monitor the voltage in the conductor pair 34 and thus to ensure that the voltage is output to the electrical appliance 8 as a load in a controlled manner. In an embodiment not shown, instead of the potting, a further standard ignition protection type is used, for example a package, for example a pressure-resistant package, a package according to the standardized ignition protection type "erhöhte Sicherheit", a sand package, an oil package, an overvoltage package.

[0051] The shunt regulator 6 is used, in addition to powering the electrical appliance 8 itself, to charge an integrated battery 81 of the electrical appliance 8. To this end, the shunt regulator 6 preferably works together with a charging regulator 61 and a limiter circuit 62, which are likewise arranged integrally in the potting 50, wherein the limiter circuit ends the charging of the battery 81 when a predefined maximum voltage is reached. In addition, a discharge circuit 63 is optionally provided. The discharge circuit is configured to discharge the charging only when the battery has a certain minimum voltage in order to protect the battery.

[0052] In Figure 6 a particularly safe embodiment of the energy source 9 with transformers 96 is shown. A total of two transformers 96 are shown, which each have two branches, wherein each branch is connected to one of the conductor pairs 31-34. These transformers 96 each have two separate, electrically separated secondary windings, to which a rectifier 97, 97' is connected in order to convert to a direct voltage. The size of this direct voltage is adjusted via a voltage regulator 98, 98', downstream of which a limiting resistor 99, 99' for limiting the current is connected.

[0053] In Figure 7 a further variant of the collector device 4 is shown. In this embodiment, the collector device 4' does not detect all conductor pairs, but only a part of these conductor pairs, namely the conductor pairs 32-34. The total current through the parallel connection of the conductor pairs 32-34 is output at a plurality of outputs 48, 48', 48'', which can be switched differently. For example, an ohmic load is arranged at the outputs 48 and 48', while a DC / DC converter 80 is provided at the output 48'' for supplying an electrical appliance 8' which works at a different voltage level.

Claims

1. Intrinsically safe energy transmission unit (1) which is suitable for use in an explosion-protected area for powering an electrical appliance (8), comprising a line connection (2) and being configured to intrinsically safely transmit electrical power from an energy source (9) having a plurality of electrically separated individual sources to the electrical appliance (8) via the line connection (2), characterized in that the line connection (2) is embodied as a multiple line having a plurality of electrically separated and individually shielded conductor pairs (31, 32, 33, 34) for connection to the individual sources, respectively, and at the appliance side end of the multiple line (3) a collector device (4) is provided which is embodied in an ignition-protected enclosure in an explosion-protected manner and has a connection end (41, 42, 43, 44) for the electrically separated conductor pairs (31, 32, 33, 34), respectively, and a combiner circuit (47), wherein the connection ends (41, 42, 43, 44) are equipped in the collector device with decoupling devices (45) which prevent a reaction on the connected conductor pairs (31, 32, 33, 34), and the combiner circuit (47, 49) is configured to combine the electrical power transmitted by the electrically separated conductor pairs (31, 32, 33, 34) at the connection ends (41, 42, 43, 44), respectively, to a total power, wherein the total power is output at an output (48) of the collector device (4) to the electrical appliance (8), wherein the conductor pairs are each equipped with their own shield (35), wherein the shields (35) are placed on one side at ground potential (36).

2. The intrinsically safe energy transfer unit of claim 1, wherein, The electrical appliance (8) is explosion-protected according to a standardized ignition protection type.

3. Intrinsically safe energy transfer unit according to any of the preceding claims, characterized in that The collector device and / or the combiner circuit are potted and / or arranged in a pressure-resistant housing.

4. The intrinsically safe energy transfer unit of claim 1, wherein, The decoupling devices have redundantly embodied decoupling elements.

5. The intrinsically safe energy transfer unit of claim 1 or 2, wherein, The combiner circuit is configured to combine the electrical currents transmitted by the conductor pairs, or the combiner circuit is configured to combine the electrical voltages transmitted by the conductor pairs.

6. The intrinsically safe energy transfer unit of claim 1, wherein, A current limitation is provided for the conductor pairs.

7. The intrinsically safe energy transfer unit of claim 1 or 2, wherein, The collector device is equipped with a voltage regulator which is configured to adjust and / or limit the voltage applied on the connection ends of the conductor pairs to a predetermined value.

8. The intrinsically safe energy transfer unit of claim 7, wherein, The connection ends are each assigned their own voltage regulator.

9. The intrinsically safe energy transfer unit of claim 1 or 2, wherein, The ground lines of the conductor pairs are insulated in the line connection and are only combined in the collector device (4) or pass through the collector device (4) in order to be combined only in the electrical appliance (8).

10. The intrinsically safe energy transfer unit of claim 1 or 2, wherein, The conductor pairs are arranged in a common sheath, and / or the line connection is equipped with a shield.

11. The intrinsically safe energy transfer unit of claim 2, wherein, The electrical appliance (8) is intrinsically safe according to Ex ia or Ex ib.

12. The intrinsically safe energy transfer unit of claim 4, wherein, The decoupling elements are embodied as current valves.

13. The intrinsically safe energy transfer unit of claim 4, wherein, The decoupling elements are embodied as passive current valves.

14. The intrinsically safe energy transfer unit of claim 12 or 13, wherein, The current valves are connected in an interference-immune series circuit in their respective decoupling devices.

15. The intrinsically safe energy transfer unit of claim 5, wherein, The combiner circuit is constructed as a parallel circuit to combine the currents transmitted by the conductor pairs.

16. The intrinsically safe energy transfer unit of claim 5, wherein, The combiner circuit is constructed as a series circuit to combine the voltages transmitted by the conductor pairs.

17. The intrinsically safe energy transfer unit of claim 6, wherein, A current limitation is provided for the conductor pairs by means of resistors.

18. The intrinsically safe energy transfer unit of claim 6 or 17, wherein, The current limitation is provided in the line connection and / or at the beginning of the line connection, in the collector device and / or on the energy source side of the line connection for the conductor pairs.

19. The intrinsically safe energy transfer unit of claim 7, wherein, The voltage regulator is implemented intrinsically safe.

20. The intrinsically safe energy transfer unit of claim 7, wherein, The voltage regulator is implemented in a shunt topology.

21. The intrinsically safe energy transfer unit of claim 9, wherein, The ground line of the conductor pairs is combined within the ignition-protected envelope.

22. The intrinsically safe energy transfer unit of claim 10, wherein, The shield is grounded on one side.

23. The intrinsically safe energy transfer unit of claim 10, wherein, The shield is grounded on the source side.

24. Inherently safe energy supply system, comprising an energy source and an energy transmission unit, which is suitable for powering an electrical device in an explosion-protected area, characterized in that the energy transmission unit is an intrinsically safe energy transmission unit (1) according to any one of claims 1 to 23.

25. The intrinsically safe energy supply system of claim 24, wherein, The energy source has a plurality of electrically separated individual sources, wherein each individual source is assigned to one of the conductor pairs, wherein the energy source and / or the individual sources have an output resistance.

26. Intrinsically safe energy supply system according to claim 24 or 25, characterized in that The collector device is implemented integrated into the electrical device.

27. Intrinsically safe energy supply system according to claim 24 or 25, characterized in that The electrical device has a battery.

28. The intrinsically safe energy supply system of claim 27, wherein, A limiter circuit is provided, which is constructed to end the charging of the battery when a predefined threshold is reached.

29. The intrinsically safe energy supply system of claim 25, wherein, wherein the energy source and / or the individual sources are current- and / or voltage-limited.

30. The intrinsically safe energy supply system of claim 26, wherein, The electrical device is a field device.

31. The intrinsically safe energy supply system of claim 26, wherein, The electrical device is an active sensor, actuator or regulator of a process technology installation.

32. The intrinsically safe energy supply system of claim 27, wherein, The electrical device has a battery with an integrated charging regulator.

33. The intrinsically safe energy supply system of claim 32, wherein, The charging regulator is constructed as a voltage-regulated control.

34. The intrinsically safe energy supply system of claim 28, wherein, A limiter circuit is provided, which is constructed to end the charging of the battery when a maximum voltage is reached.

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