DE102018107423B4 - Method and system for assigning phases in a multi-phase alternating current low-voltage network outlet with several multi-phase connection points - Google Patents

Abstract

Method for assigning phases (L1, L2, L3) in a multi-phase alternating current low-voltage network outlet (2) with several multi-phase connection points (4.1 - 4.N), - for the measured values of an electrical measured variable of the individual phases of a first and the individual phases of a second of the several multi-phase connection points (4.1 - 4.N) are received, - in which a value (Στ) is determined for a correlation measure for several possible candidate phase assignments (I - VI) of the individual phases of the first multi-phase connection point to the individual phases of the second multi-phase connection point , whereby the value (Στ) for the correlation measure is determined in each case as a function of the received measured values of the electrical measured variable, and - in which, depending on the determined values (Στ) for the correlation measure, a candidate phase assignment from the multiple candidate phase assignments (I - VI) is selected, characterized in - that the phases of the multi-phase connection points (4.1 - 4.N) of the polyphase alternating current low-voltage network outlet (2) by assigning the individual phases of adjacent polyphase connection points in the polyphase alternating current low-voltage network outlet (2) to one another.

Description

The invention relates to a method for assigning phases in a multi-phase alternating current low-voltage network outlet with several multi-phase connection points and a system for carrying out the method. The invention also relates to a method for selecting a phase of a multi-phase connection point in a multi-phase alternating current low-voltage network outlet for connecting an energy consumer or an energy feeder, as well as a method for determining a fault in a multi-phase alternating current low-voltage network outlet.

In Germany, low-voltage distribution networks are mainly set up symmetrically in three phases. An asymmetrical load distribution over the three phases (hereinafter referred to as L1, L2, L3) leads in the worst case to a loss of up to 85% of the power transmission capacity compared to the symmetrical phase load. It is therefore desirable to distribute energy consumers or also decentralized feed systems such as photovoltaic systems to the three phases in order to achieve the most symmetrical phase utilization possible. In particular, it is desirable to achieve a symmetrical phase load within a low-voltage network outlet.

At the individual multi-phase connection points, for example house connections, of a low-voltage network outlet, the phases tapped from the low-voltage network outlet are usually labeled or color-coded (e.g. brown for L1, black for L2 and gray for L3). These local identifications of the individual phases at a multiphase connection point n are referred to below as L1 _n , L2 _n , L3 _n (etc. in the case of more than three phases). L1 ₁ , L2 ₁ and L3 ₁ are therefore the local identifications of the three phases at a first multiphase connection point and L1 ₂ , L2 ₂ and L3 _{2 are} the local identifications of the three phases at a second multiphase connection point.

Investigations in low-voltage distribution networks have shown, however, that the phases at the individual multi-phase connection points (mainly house connections) are not systematically assigned. For example, a single phase can be identified as “L1” at a first connection point, but as “L2” at an adjacent second connection point. In other words, for example, L1 ₁ and L2 _{2 can} tap from the same phase, but L1 ₁ and L1 ₂ from different phases of the low-voltage network outlet.

This is due to unintentional phase shifts in the historically grown networks and is almost inevitable. As a result of this ambiguous assignment of the individual phases, a consistent symmetrical load distribution is only possible with great difficulty. A physical renaming or rewiring of the low-voltage networks (with network lengths of a few thousand kilometers) is financially and logistically not feasible.

In the article "Consumer Phase Identification in a Three Phase Unbalanced LV Distribution Network" by H. Pezeshki and PJ Wolfs (ISBN 978-11-4673-2597-4, pp. 1-7) describes a method that enables automatic phase identification at house connections.

In the US 2016/0 109 491 A1 describes a method for determining the topology of a network section of an AC network.

In the DE 10 2015 105 152 A1 discloses a method for reducing an unbalanced load in a three-phase distribution network.

Against this background, the present invention is based on the object of proposing a method with which phases in a multi-phase alternating current low-voltage network outlet can be assigned.

This object is achieved according to the invention by a method for assigning phases in a multi-phase alternating current low-voltage network outlet with several multi-phase connection points, in which measured values of an electrical measured variable of the individual phases of a first and the individual phases of a second of the several multi-phase connection points are received, in which for several possible candidates -Phase assignments of the individual phases of the first multi-phase connection point to the individual phases of the second multi-phase connection point, a value for a correlation measure is determined, the value for the correlation measure being determined depending on the received measured values of the electrical measured variable, and depending on the determined values for the Correlation measure a candidate phase assignment is selected from the plurality of candidate phase assignments.

Furthermore, the above-mentioned object is achieved by a system comprising a server which is set up to carry out the method described above. Furthermore, the system preferably has communication connections to a plurality of measuring devices, which are each assigned to a multi-phase connection point in a multi-phase alternating current low-voltage network outlet.

The method and the system make it possible to virtually symmetrize the multi-phase connection points on the basis of the measured values received, i.e. to assign the individual phases of several multi-phase connection points in a low-voltage network outlet to one another in such a way that it corresponds to the actual laying situation.

In this way, for example, a multi-phase alternating current low-voltage network outlet can be mapped with regard to the actual phases at the individual multi-phase connection points, so that balancing can be achieved more easily through a targeted selection of energy consumers to be installed or decentralized feed systems.

In this way, network balancing can be achieved when evaluating the connection of asymmetrical devices. In addition, it is possible to systematically record and improve highly asymmetrical networks. In this way, the power transmission capacity of the networks can be better utilized, so that unnecessary network expansion can be avoided.

The method is used to assign phases in a multi-phase alternating current low-voltage network outlet. A low-voltage network outlet typically starts from a transformer station through which the low-voltage network outlet is fed from the medium-voltage network. The low-voltage network outlet includes lines for the individual phases, for example three lines for the three phases L1, L2 and L3 for the three-phase alternating current common in Germany, among other places. In addition, the low-voltage network outlet preferably also includes a line for the usually combined neutral and protective conductor.

The low-voltage network outlet has several multi-phase connection points. A multi-phase connection point is understood to mean a connection to the low-voltage network outlet at which several phases are tapped from the low-voltage network outlet. The multi-phase connection points can be house connections, for example.

In the method, measured values of an electrical measured variable of the individual phases of a first and of the individual phases of a second of the plurality of multiphase connection points are received. Measured values for the voltage level or for the current intensity are particularly suitable as measured values of an electrical measured variable. The measured values are preferably received directly or indirectly, for example via a buffer, from measuring devices provided at the individual multi-phase connection points, which are set up to measure measured values of an electrical measured variable of the individual phase, in particular measured values for the voltage, in particular the voltage level, and / or the current, in particular to measure the amperage on the individual phases.

The received measurement values are preferably assigned to a predetermined measurement time, for example by means of a time stamp assigned to the measurement values.

The measured values can be punctual measured values, for example at a specific measurement time. However, the measured values are preferably sequences of measured values which indicate the course of the electrical measured variable over time, for example in the form of a voltage or current-time course. The measured values can in particular be effective values that are averaged over a predetermined period of, for example, 1 s. The measured values can accordingly be present, in particular, in the form of a voltage level rms value or current intensity rms value-time curve. Such a voltage level rms value-time curve can contain, for example, the voltage level-time curve over an hour in the form of 3600 voltage values averaged over 1 s.

In the method, a value for a correlation measure is determined in each case for several possible candidate phase assignments of the individual phases of the first polyphase connection point to the individual phases of the second polyphase connection point. With a first three-phase connection point (with the local phase identifications L1 ₁ , L2 ₁ and L3 ₁ ) and a second three-phase connection point (with the local phase identifications L1 ₂ , L2 ₂ and L3 ₂ ) there are, for example, six possible assignments I to VI of the individual phases to one another according to the following table: Assignment number I. II III IV V VI Assignment of the phases L1 ₁ ↔ L1 ₂ L1 ₁ ↔ L2 ₂ L1 ₁ ↔ L3 ₂ L1 ₁ ↔ L1 ₂ L1 ₁ ↔ L2 ₂ L1 ₁ ↔ L3 ₂ L2 ₁ ↔ L2 ₂ L2 ₁ ↔ L1 ₂ L2 ₁ ↔ L1 ₂ L2 ₁ ↔ L3 ₂ L2 ₁ ↔ L3 ₂ L2 ₁ ↔ L2 ₂ L3 ₁ ↔ L3 ₂ L3 ₁ ↔ L3 ₂ L3 ₁ ↔ L2 ₂ L3 ₁ ↔ L2 ₂ L3 ₁ ↔ L1 ₂ L3 ₁ ↔ L1 ₂

For several or even each of the possible candidate phase assignments I to VI, a value for a correlation measure can now be determined as a function of the received measured values of the electrical measured variables. For this purpose, in particular, the measured values of a phase of the first multi-phase connection point are combined with the measured values of the phase of the second multi-phase connection point assigned according to a candidate phase assignment, the measured values of a second phase of the first multi-phase connection point with the measured values of the phase of the second assigned according to this candidate phase assignment Multi-phase connection point, etc. correlated with each other in order to determine the correlation measure for this candidate phase assignment.

In the method, depending on the determined values for the correlation measure, a candidate phase assignment is selected from the multiple candidate assignments (e.g. from the above candidate phase assignments I to VI). The candidate phase assignment is preferably selected for which the greatest correlation of the phases assigned to one another could be determined. With this candidate phase assignment, there is the greatest probability that the phases assigned to one another also match in terms of interconnection.

Various embodiments of the method and the system are described below, the individual embodiments applying to both the method and the system and also being combinable with one another.

In a first embodiment, the measured values for the electrical measured variable of the individual phases of a multi-phase connection point are each received by a measuring device assigned to this multi-phase connection point. In particular, a measuring device, in particular a so-called smart meter, can be provided at each multi-phase connection point, which is set up on the one hand to measure the voltage, in particular the voltage level, and / or the current, in particular the current strength, of an individual phase of the multi-phase connection point and on the other hand is set up to measure it is to transmit the measured values to a central point, in particular to a server. In the meantime, more and more households are being equipped with modern measuring systems, in particular smart meters, which, on the one hand, record the required measured values and transmit them to a central point where the data can be evaluated.

In a further embodiment, measured values for the voltage level or for the current intensity are received as measured values for an electrical measured variable. It has been shown that phase assignment can be reliably achieved by correlating voltage level or current strength values.

In a further embodiment, to determine a value for the correlation measure for a candidate phase assignment, a respective correlation coefficient is initially used for each phase of the first multi-phase connection point as a function of the received measured values of this phase and of the received measured values of the phase assigned to this phase according to the candidate phase assignment second polyphase connection point determined and the value for the correlation measure is determined depending on the determined correlation coefficient. A possible correlation coefficient is, for example, Kendall's correlation coefficient τ. The greater the value of τ, the stronger the correlation between the measured values of the phases assigned to one another.

To determine the value for the correlation measure, the correlation coefficients of the phases assigned according to a candidate phase assignment can be added, for example. The greater this sum of the correlation coefficients for a candidate phase assignment is compared to other candidate phase assignments, the higher the probability that this candidate phase assignment is the correct phase assignment.

For the candidate phase assignment II described above, for example, a first Kendall correlation coefficient τ ₁ can initially be used depending on the measured values of phases L1 ₁ and L2 ₂ , a second correlation coefficient τ ₂ depending on the measured values of phases L2 ₁ and L1 ₂ and a third correlation coefficient τ _{3 is} calculated depending on the measured values of the phases L3 ₁ and L3 ₂ and then the correlation measure T _II for the candidate phase assignment II is calculated _{from τ 1} , τ ₂ and τ _{3 , for example as T II} = τ ₁ + τ ₂ + τ ₃ .

In a further embodiment, several phase selection cycles are carried out to assign the phases of the first and second multi-phase connection point, preferably at regular time intervals of, for example, one day, each phase selection cycle depending on the respective reception of measured values for the electrical measured variable and a respective determination of the values for the correlation measure of the measured values for the electrical measured variable and a respective selection of a phase assignment depending on the values for the correlation measure, and after several phase selection cycles have been carried out, a phase assignment is made from the phase assignments selected in the respective phase selection cycles depending on the frequency with which the individual phase assignments are selected for performing the multiple phase selection cycles.

A phase selection cycle thus comprises a selection of a phase assignment from a plurality of possible candidate phase assignments based on the received measured values, for example from a point in time or from a time interval. When such a phase selection cycle is carried out once, the phases can be misallocated, for example if a temporary network disturbance leads to a misallocation of the phases happening to show a better correlation than the actually correct allocation. By carrying out several phase assignment cycles, for example daily over a period of one or two weeks, and then selecting the phase assignment that was selected most frequently in the phase assignment cycles, the reliability of the phase assignment selection can be increased, even if it is too occasional in the network temporary network disturbance occurs.

In a further embodiment, the phases of the first, second and third polyphase connection point are assigned by determining a phase assignment of the individual phases of the first and second polyphase connection point and a phase assignment of the second and third polyphase connection point or of the first and third polyphase connection point. In the case of more than two multi-phase connection points, the phase assignment is accordingly preferably carried out in pairs, so that the phases of two multi-phase connection points are assigned to one another. In this way, the phase position at all considered multi-phase connection points can gradually be assigned to one another in order to thereby preferably map the entire low-voltage network outlet with regard to its phase position.

A phase assignment is preferably determined in each case for neighboring multi-phase connection points, since the matching phases of neighboring multi-phase connection points show a better correlation than multi-phase connection points that are further apart and thus a reliable allocation of the phases is possible.

According to the invention, the phases of the multi-phase connection points of a multi-phase alternating current low-voltage network output are assigned to one another by assigning the individual phases of adjacent multi-phase connection points in the multi-phase alternating current low-voltage network output to one another, in particular starting from a last multi-phase connection point in the multi-phase alternating current low-voltage network output. For example, in order to map the phases of a low-voltage network outlet, the phases of the last multi-phase connection point, i.e. the one furthest away from the transformer station, can be assigned to the phases of the adjacent (penultimate) multi-phase connection point before the phases of the penultimate multi-phase connection point are assigned to the phases of the adjacent (penultimate) multi-phase connection point assigned etc.

The method described above for assigning phases in a multi-phase alternating current low-voltage network output with several multi-phase connection points and the described embodiments thereof make it possible to reliably map the individual phases at the multi-phase connection points of a multi-phase alternating current low-voltage network output, so that the actual connection configuration of the individual phases at the individual multi-phase connection points , for example in a database.

Such a mapping can preferably be used to symmetrize the respective phase load in the relevant low-voltage network outlet.

According to a second aspect of the present invention, the above-mentioned object is further achieved according to the invention by a method for selecting a phase of a multi-phase connection point in a multi-phase alternating current low-voltage network outlet for connecting an energy consumer or an energy feeder, in which location information about the location of the planned connection is received , in which, depending on the received location information, an associated multi-phase alternating current low-voltage network output and an associated multi-phase connection point are selected in the multi-phase alternating current low-voltage network output, in which information about the phase to be selected in the selected multi-phase alternating current low-voltage network output for an energy consumer or an energy feeder, as well as information about the phase assignment can be retrieved at the selected multi-phase connection point and in which one exercises on the retrieved information r the phase to be selected in the selected polyphase alternating current low-voltage network outlet for an energy consumer or an energy feeder and the message based on the retrieved information about the phase assignment at the selected polyphase connection point is generated and sent.

The energy consumer or the energy feeder is, in particular, an asymmetrical energy consumer or energy feeder that is not connected to all phases of the multi-phase connection point or the low-voltage network outlet, in particular only to one phase.

The method described above enables the installer on site to connect electrical devices (energy consumers or energy feeders) in the correct phase in low-voltage distribution networks in order to achieve a symmetry of the phase load. The information available about the clear phase assignment at the multi-phase connection points can be used to achieve network balancing.

In the method, location information about the location of the planned connection is received. The location information can be, for example, coordinates that were determined, for example, by means of a GPS receiver.

Depending on the received location information, an associated multi-phase alternating current low-voltage network outlet and an associated multi-phase connection point in this multi-phase alternating current low-voltage network outlet are selected. For this purpose, a database is preferably used in which various multi-phase alternating current low-voltage network outlets and / or multi-phase connection points in the multi-phase alternating current low-voltage network outlets are assigned location information. The database can include, for example, digital map material for the actual connection situation.

In the method, information about the phase to be selected in the selected multi-phase alternating current low-voltage network outlet for an energy consumer or an energy feeder is retrieved. The retrieved information can in particular contain information about the least loaded phase for the connection of an energy consumer or about the most heavily loaded phase for the connection of an energy feeder.

Information about the phase assignment at the selected multi-phase connection point is also called up. The information about the phase assignment at the selected multiphase connection point preferably includes information about the local identification of the phase to be selected for the connection of an energy consumer or an energy feeder.

The virtual phase assignment in a low-voltage network outlet required to provide this information can in particular be carried out with the previously described method for assigning phases in a multi-phase alternating current low-voltage network outlet with several multi-phase connection points. Accordingly, the information about the phase assignment at the selected polyphase connection point has preferably been provided beforehand by determining the phase assignment using the method described above for assigning phases in a polyphase alternating current low-voltage network outlet with several polyphase connection points and the information about the Phase assignment at the selected multi-phase connection point as a function of the phase assignment determined with the method.

For example, with the previously described method for assigning phases in a multi-phase alternating current low-voltage network outlet with several multi-phase connection points, a database can be generated which contains the respective phase assignment for a large number of possible multi-phase alternating current low-voltage network outputs and the multi-phase connection points contained therein.

In the method, a message based on the read information about the phase to be selected in the selected polyphase alternating current low-voltage network outlet for an energy consumer or an energy supplier and on the information read out about the phase assignment at the selected polyphase connection point is generated and sent. The message can contain, for example, the separate information which phase is to be selected for the connection of the energy consumer or energy feeder (L1, L2 or L3) and how this phase is identified at the corresponding multi-phase connection point (L1 _n , L2 _n , L3 _n ). Alternatively, a preliminary evaluation can also be carried out for the generation of the message, so that the message only contains information about the phase to be selected for the connection of the energy consumer or energy feeder, which corresponds to the local identification at the corresponding multi-phase connection point.

In a further embodiment, the provision of the information about the phase assignment at the selected multi-phase connection point is repeated at predetermined time intervals. For this purpose, the method described above for assigning phases in a multi-phase alternating current low-voltage network outlet with several multi-phase connection points is preferably repeated at certain time intervals, for example every one to four weeks, in order to be able to record changes as a result of civil engineering work or connection work. If, for example, a phase assignment in a low-voltage network outlet is changed due to connection or civil engineering work, this will be recorded or ascertained the next time the method for assigning phases is carried out, so that the database is up-to-date again within a short time.

In a further embodiment, location information transmitted by a mobile device, for example a smartphone, is received as location information and the generated message is sent to the mobile device. An app can be installed on the mobile device, for example, which transmits location information to a server at the request of the user, for example from a GPS receiver of the mobile device, on which the previously described method for selecting a phase of a multi-phase connection point in a multi-phase alternating current -Low voltage network outlet is carried out. The message generated and sent by the server about the phase to be selected for connecting the energy consumer or energy feeder to the multi-phase connection point assigned to the location information can then be received and displayed by the mobile device. In this way, an installer at the installation site can call up the phase to which he should connect an asymmetrical device in order to achieve a balancing of the low-voltage network outlet.

It was also found that the phase mapping or virtual phase assignment, which can be achieved by the previously described method for assigning phases in a multi-phase alternating current low-voltage network outlet with several multi-phase connection points, can also be used to identify errors at an early stage.

Accordingly, the above-mentioned object is achieved according to a further aspect of the invention by a method for determining a fault location in a polyphase alternating current low-voltage network outlet, in which information about the phase assignment of the respective polyphase connection point is retrieved for a first and a second polyphase connection point in a polyphase alternating current low-voltage network outlet in which the individual phases of the first multi-phase connection point are assigned to the individual phases of the second multi-phase connection point on the basis of the information retrieved about the respective phase assignment and in which several voltage adjustment cycles are carried out, preferably at regular time intervals, with values for the voltage level of the individual phases in each voltage adjustment cycle of the first and the second polyphase connection point are received, the received values for the voltage level of the individual phases of the first M. multi-phase connection point are compared with the received values for the voltage level of the respectively assigned phases of the second polyphase connection point and, depending on the result of the comparison, it is determined whether there is an error at the first or second polyphase connection point, an error message being output or sent when an error is determined.

In this way, in the event of a sudden and possibly also temporary discrepancy between two phases assigned to one another by means of virtual balancing, it can be determined whether there is an error in this phase, for example due to a defective terminal point with increased resistance.

In the voltage balancing cycles, the voltage levels of the individual phases of multiple multi-phase connection points that are assigned to one another are compared with one another. When comparing the received values for the voltage level of the individual phases of the first polyphase connection point with the received values for the voltage level of the respectively assigned phases of the second polyphase connection point, for example, for two mutually assigned phases, for example, a value for a correlation measure depending on the values received for these phases can be determined for the stress level.

To determine whether there is a fault at the first or second multi-phase connection point, a comparison of a current voltage adjustment cycle can be compared with the adjustment of an earlier voltage adjustment cycle, for example the values determined for two mutually assigned phases for a correlation measure in an earlier and in the current voltage adjustment cycle. A reduction in the correlation value between two assigned phases compared to a value from an earlier voltage adjustment cycle can indicate an error.

In the comparison or in the determination of whether there is an error, it is preferably taken into account whether a special switching state or a planned supply interruption could have led to a deviation in the phases assigned to one another. These time windows with special switching states or planned supply interruptions are to be excluded from the comparison or error determination.

In the method, a previously provided information about the respective phase assignment at the first and the second polyphase connection point is preferably retrieved, the information about the respective phase assignment at the first and the second polyphase connection point being provided beforehand by the phase assignment using the previously described method for assignment of phases in a polyphase alternating current low-voltage network outlet with several polyphase connection points and the information about the respective phase assignment at the first and second polyphase connection point is generated depending on the respective phase assignment determined with the method for assigning phases in a polyphase alternating current low-voltage network outlet with several polyphase connection points.

Further features and advantages of the previously described method and the system emerge from the following description of exemplary embodiments, reference being made to the accompanying drawings.

• 1 einen Mehrphasenwechselstrom-Niederspannungsnetzabgang mit mehreren Mehrphasenanschlusspunkten in schematischer Darstellung,
• 2a-c Phasenabgriffe an verschiedenen Mehrphasenanschlusspunkten aus 1 in schematischer Darstellung,
• 3 ein Ausführungsbeispiel des Verfahrens zur Zuordnung von Phasen in einem Mehrphasenwechselstrom-Niederspannungsnetzabgang mit mehreren Mehrphasenanschlusspunkten,
• 4a-b Spannungsverläufe von einzelnen Phasen eines ersten und eines zweiten Mehrphasenanschlusspunktes,
• 5 sechs verschiedene mögliche Kandidaten-Phasenzuordnungen I bis VI,
• 6 die Auswahl einer Phasenzuordnung aus den Kandidaten-Phasenzuordnungen abhängig vom Wert für das Korrelationsmaß,
• 7 die Auswahl einer Phasenzuordnung aus den mehreren Kandidaten-Phasenzuordnungen in Abhängigkeit von der Häufigkeit der Auswahl in mehreren Phasenauswahlzyklen,
• 8 ein Ausführungsbeispiel des Verfahrens zur Auswahl einer Phase eines Mehrphasenanschlusspunktes in einem Mehrphasenwechselstrom-Niederspannungsnetzabgang zum Anschluss eines Energieverbrauchers oder eines Energieeinspeisers,
• 9 eine beispielhafte Darstellung einer mit dem Verfahren aus 8 erzeugten Nachricht und
• 10 ein Ausführungsbeispiel des Verfahrens zur Ermittlung einer Fehlerstelle in einem Mehrphasenwechselstrom-Niederspannungsnetzabgang.

Show in the drawing

• 1 a multi-phase alternating current low-voltage network outlet with several multi-phase connection points in a schematic representation,
• 2a-c Phase taps at different multi-phase connection points 1 in a schematic representation,
• 3 an embodiment of the method for assigning phases in a multi-phase alternating current low-voltage network outlet with several multi-phase connection points,
• 4a-b Voltage curves of individual phases of a first and a second multi-phase connection point,
• 5 six different possible candidate phase assignments I to VI,
• 6th the selection of a phase assignment from the candidate phase assignments depending on the value for the correlation measure,
• 7th the selection of a phase assignment from the several candidate phase assignments depending on the frequency of the selection in several phase selection cycles,
• 8th an embodiment of the method for selecting a phase of a multi-phase connection point in a multi-phase alternating current low-voltage network outlet for connecting an energy consumer or an energy feeder,
• 9 an exemplary representation of a with the method 8th generated message and
• 10 an embodiment of the method for determining a fault location in a polyphase alternating current low-voltage network outlet.

1 shows a polyphase alternating current low-voltage network outlet 2 with several multi-phase connection points 4.1 to 4.N in a schematic representation. The low-voltage network outlet 2 runs from a transformer station 6th that the low-voltage network outlet 2 Supplied from the medium-voltage network, along a specified route, for example as an underground cable.

The low-voltage network outlet 2 is in the present case designed as a three-phase alternating current low-voltage network outlet and comprises four lines, namely the three phases L1, L2 and L3 and a PEN conductor, with in 1 for the sake of clarity, only the three phases L1, L2 and L3 are shown.

In the course of the low-voltage network outlet 2 arranged multi-phase connection points 4.1 to 4.N it can be, for example, house connections through the low-voltage network outlet 2 be supplied electrically. At the multi-phase connection points 4th the individual phases L1, L2 and L3 as well as the PEN conductor (not shown for the sake of clarity) from the low-voltage network outlet 2 tapped, typically in branch sleeves provided for this purpose 8th .

There is an electricity meter at each multi-phase connection point 10 provided, which can in particular be so-called smart meters.

The identification of the individual phases at each multi-phase connection point (e.g. by labeling or color coding) are in 1 referred to as L1 _n , L2 _n and L3 _n , where the index n is the number of the multi-phase connection point. L1 ₁ , L2 ₁ and L3 ₁ are therefore the local phase identifications at the multi-phase connection point 4.1 .

Since many low-voltage networks have grown historically, the assignment of the individual phases is in the low-voltage network outlet 2 with a high probability not consistently throughout. L1 ₁ , L1 _n , L1 _N-1 and L1 _N therefore do not necessarily designate the same phase. This inconsistency means that a specific phase, for example "L1", cannot be used uniformly in a low-voltage network outlet, since this phase designation can designate different phases at the individual multi-phase connection points.

The 2a-c show an example of the phase taps in the sleeves 8th three different multi-phase connection points 1 in schematic representation and illustrate a common cause of discrepancies in the phase assignment.

2a shows the phase taps from the low-voltage network outlet 2 at the last multi-phase connection point 4.N . The local identifications of phases L1 _N , L2 _N and L3 _N match at this multi-phase connection point with phases L1, L2 and L3 of the low-voltage network outlet 2 match.

2 B shows the phase taps from the low-voltage network outlet 2 at the penultimate multi-phase connection point 4.N-1 . At this multi-phase connection point, the local identifications of phases L1 _N , L2 _N and L3 _N do not match phases L1, L2 and L3 of the low-voltage network outlet 2 match. As a result, L1 _N-1 and L1 _N are not on the same phase, although they are locally identified as "L1" (eg by labeling or color coding).

2c shows the phase taps from the low-voltage network outlet 2 at another multi-phase connection point 4.n . At this multi-phase connection point, the local identifications of phases L1 _N , L2 _N and L3 _N do not match either phases L1, L2 and L3 of the low-voltage network outlet 2 and therefore not with the local phase identification at the multi-phase connection point 4.N , still with the local phase identification at the multi-phase connection point 4.N-1 match.

3 now shows an embodiment of the method for assigning phases in the polyphase alternating current low-voltage network outlet 2 with several multi-phase connection points 4.1 - 4.N .

The first step in the process is 20th First a reference connection point is defined, from which the assignment in the low-voltage network outlet is based 2 should take place. As a reference connection point is preferably the furthest from the transformer station 6th remote polyphase connection point 4.N selected.

In the next step 22nd the next connection point is selected, the phases of which are to be assigned to the phases of the reference connection point. This is preferably initially the reference connection point adjacent to the reference connection point 4.N-1 .

In the next step 24 the time window is determined in which the phase selection cycles for the assignment of the phases are to be carried out. The time window preferably comprises several days, for example two weeks, so that occasional temporary network disturbances during individual phase selection cycles are less significant. The time window is preferably completely in the past, so that the measured values from the time window required to carry out the method are already completely available.

In the next step 26th the start date for the first phase selection cycle is set, which in particular coincides with the start of the previously determined time window.

In the next step 28 are from the electricity meter 10 of the reference connection point 4.N and from the electricity meter 10 of the neighboring reference connection point 4.N-1 measured voltage values of the individual phases of the multi-phase connection points 4.N and 4.N-1 receive. These measured values can be obtained from the respective counters 10 , especially smart meters, at the corresponding connection points 4.N and 4.N-1 are received, preferably via a buffer 30th into which the electricity meter 10 of the individual multi-phase connection points transmit their measurement data. In particular, on the buffer 30th the measurement data can be stored for the entire time window, so that the measurement data are stored from the intermediate memory when the method described here is carried out 30th can be accessed.

The 4a-b show exemplary received measured values in the form of voltage curves of the individual phases at the multi-phase connection points 4.N ( 4a) and 4th .N-1 ( 4b) . The received measured values each include time information, for example a time stamp, so that simultaneous voltage values at the individual phases of the individual multi-phase connection points can be assigned to one another.

In the next step 32 the received data can be checked and, if necessary, corrected.

In the next steps 34 and 36 are for several possible candidate phase assignments of the individual phases of the multi-phase connection point 4.N to the phases of the multi-phase connection point 4.N-1 Values for a correlation measure determined. 5 shows the six possible candidate phase assignments I to VI in the present case for assigning the local phase identifications L1 _N , L2 _N , L3 _N at the multi-phase connection point 4.N to the local phase markings L1 _N-1 , L2 _N-1 , L3 _N-1 at the multi-phase connection point 4.N-1 .

To calculate the values for the correlation measure of the individual candidate phase assignments, in step 34 First correlation coefficients, preferably Kendall's τ, are calculated for the assignment of individual phases to one another, for example for L1 _N ↔ L1 _N-1 , L1 _N ↔ L2 _N-1 , L1 _N ↔ L3 _N-1 , L2 _N ↔ L1 _N-1 etc. ., based on the in 2a and 2 B voltage curves shown that were received for the relevant phases. For the assignment L1 ↔ _N L1 _N-1 is calculated, for example, Kendall's correlation coefficient τ (L1 ↔ _N L1 _N-1) based on the voltage waveforms U _(N L1) and U (L1 _N-1).

In step 36 the correlation coefficients for the individual phase assignments of the respective candidate phase assignments I to VI are added in order to obtain a value for the degree of correlation of the relevant candidate phase assignment. For the candidate phase assignment I, the correlation measure then yields, for example, the value Στ (phase assignment I) = τ (L1 _N ↔ L1 _N-1 ) + τ (L2 _N ↔ L2 _N-1 ) + τ (L3 _N ↔ L3 _N-1 ).

In the next step 28 that one of the candidate phase assignments I to VI is selected whose value Στ for the correlation measure corresponds to the greatest correlation. 6th shows an example of the values Στ determined for the candidate phase assignments I to VI for the correlation measure as a diagram. Accordingly, the largest value Στ results for the candidate phase assignment II, so that this candidate phase assignment II is selected as the phase assignment in the first phase selection cycle described here.

In the next step 40 the start date is postponed by, for example, 24 hours to select the start date for the next phase selection cycle.

In the next step 42 it is checked whether the new start date is still within the previously in step 24 specified time window. If this is the case, there is a return to step 28 to carry out the next phase selection cycle for the assignment of the individual phases of the multi-phase connection points 4.N and 4.N-1 .

7th shows an example of the results of several phase selection cycles 1 to 9, ie the candidate assignment selected in each case in the individual phase selection cycles. How out 7th It can be seen that due to temporary network disturbances it can happen that different candidate phase assignments are selected in the individual phase selection cycles.

If the new start date after going through the steps several times 28 to 40 finally falls outside the time window, the procedure starts with step 44 continued, in which from the candidate phase assignments I to VI that candidate phase assignment is selected which was most frequently selected in the previously performed phase selection cycles. In 7th this is the candidate assignment II, which in the process is used as the final phase assignment between the phases of the multi-phase connection points 4.N and 4.N-1 is selected. This phase assignment is then preferably stored in a database 46 saved.

To assign the phases of further multi-phase connection points in the low-voltage network outlet 2 there is a return to the step 22nd . The next multi-phase connection point is then determined in this, preferably the one for the last multi-phase connection point considered 4.N-1 neighboring multi-phase connection point 4.N-2 . In the further steps 24 to 42 is then the phase assignment of the individual phases of the multi-phase connection point 4.N-2 to the phases of the multi-phase connection point 4.N-1 selected.

The phase assignments for the multi-phase connection points are successively made in corresponding further loop passes 4.N-3 and 4.N-2 , 4.N-4 and 4.N-3 up to 4.1 and 4.2 determined in pairs, so that the phases of the low-voltage network outlet 2 are finally fully mapped. In this way, the local phase identifications of the phases are at the individual multi-phase connection points 4th the network-side phases of the low-voltage network outlet 2 clearly assignable. This phase mapping of the low-voltage network outlet 2 is in the database 46 saved.

With such a mapping of the phases of the low-voltage network outlet 2 When installing asymmetrical devices, energy consumers or energy feeders, you can work towards a balancing of the load of the individual phases, since the balancing of the low-voltage network outlet 2 allows the phase to be selected for the installation of the device to be clearly determined locally at the respective multi-phase connection point.

8th shows an embodiment of the method for selecting a phase of a polyphase connection point in a polyphase alternating current low-voltage network outlet 2 for connecting an energy consumer or an energy feeder.

In the present case, the process is carried out on a server 60 performed with a mobile device 62 , for example a smartphone, a user directly or indirectly, for example via an intermediary server or an intermediary cloud 70 can communicate. On the mobile device 62 For example, an app can be installed that is set up to connect to the server 60 create messages to be sent or from the server 60 process received messages.

An installer who wants to connect an asymmetrical energy consumer, for example a charging station for electric vehicles, or an asymmetrical energy feeder, for example a photovoltaic system, to a specific multi-phase connection point of a low-voltage network outlet, for example to a specific house connection, can use such an app on the mobile device 62 Determine the phase to be selected for this, taking into account the local phase identification at the relevant multi-phase connection point.

For this purpose, the app is on the mobile device 62 set up in response to a corresponding user input 64 the user's current position of the mobile device 62 via one in the mobile device 62 to determine the intended GPS receiver ( 66 in 8th ) and a request with location information about the current position to the server 60 to send ( 68 in 8th ).

On the server 60 the method for selecting a phase of a multi-phase connection point in a multi-phase alternating current low-voltage network outlet for connecting an energy consumer or an energy feeder is carried out. This is done in step 72 those from the mobile device 62 received request sent with the location information contained therein.

In the next step 74 determines the server 60 , which low-voltage network outlet and which multi-phase connection point in the low-voltage network outlet is assigned to the corresponding location information. The server intervenes for this purpose 60 on a database 46 zu, in which the location information of various multi-phase connection points and the associated low-voltage network outlets are stored.

In the next step 76 the server determines 60 , again by accessing the database 46 , the phase of the previously determined low-voltage network output that is to be selected for connecting an energy consumer or an energy feeder in order to achieve a balancing of the low-voltage network output. The phase to be selected for connecting an energy consumer can, in particular, be the phase with the least load on the low-voltage network outlet. The phase to be selected for connecting an energy feeder can in particular be the phase of the low-voltage network outlet that is most heavily loaded (by consumers).

In the next step 78 the server determines 60 the phase assignment for the previously determined multi-phase connection point in the low-voltage network outlet. To do this, the server accesses the database again 46 to, which contains information about the phase assignments at the multi-phase connection points of the low-voltage network outlet, which was previously based on the 3 procedures described were determined.

In the next step 80 the server generates a message based on the previous step 76 and step 78 determined information and sends it to the mobile device 62 on which the message can be received and displayed ( 80 in 8th ).

9 shows an exemplary representation 90 such a message on the mobile device 62 . The message includes information 92 to the multi-phase connection point in the low-voltage network outlet determined on the basis of the location information. This information is in 9 shown as the address of the corresponding house connection. The message also includes an overview 94 via the network-side phases, ie the phases of the low-voltage network outlet, and the associated local phase identifications at the relevant house connection. In this way, the installer can clearly assign the phase identification at the house connection point to the higher-level phases in the low-voltage network outlet. Finally contains the representation 90 one more information 96 via the phase to be used for connecting an energy consumer ("V") or an energy feeder ("E").

According to 9 the installer should therefore select phase L3 of the low-voltage network outlet to connect an energy consumer, for example a charging station for an electric vehicle, which is locally identified as phase "L2" at the house connection point.

One with the in 3 The method presented here determined mapping of the phases of a multi-phase alternating current low-voltage network outlet 2 can also be used to determine possible faults in the polyphase alternating current low-voltage network outlet.

10 shows an exemplary embodiment of the method for determining a fault location in a polyphase alternating current low-voltage network outlet. The procedure is also carried out on the server 60 carried out. In step 112 are initially for various multi-phase connection points in a low-voltage network outlet 2 Information about the phase assignment of the individual phases of the respective multi-phase connection points 4th retrieved from the database 46 . This in the database 46 The information contained therein was previously determined by executing the in 3 described procedure.

In the next step 114 voltage values of the individual phases of the multi-phase connection points are called up, either from the electricity meters designed as smart meters 10 at the individual multi-phase connection points 4.1 to 4.N , preferably from a buffer in which the electricity meter 10 transmit corresponding measured values.

In the next step 116 the voltage values of the according to the in step 112 retrieved phase assignments matched to each other, assigned phases of the individual multi-phase connection points. For this purpose, for example, the mean voltage difference between the mutually assigned phases of, for example, two adjacent multiphase connection points can be calculated. Alternatively or additionally, a value for a correlation measure can be determined depending on the voltage values or curves of two phases that are respectively assigned to one another.

In the next step 118 it is checked how much the determined deviations of the voltage values of the phases assigned to one another differ in relation to earlier deviations determined between these phases. In this check, it is preferably taken into account whether a special switching state or a planned supply interruption could have led to this deviation. Time windows with special switching states or planned supply interruptions are to be excluded from the review.

When checking, changes in the deviations between the voltage values compared to previous deviations can indicate a network fault.

For example, on one phase there can be a larger mean voltage deviation between two adjacent multi-phase connection points if the corresponding phase tap is in one of the branch joints 8th this polyphase connection points has an increased resistance.

A network fault can also indicate if there was a high correlation between two phases assigned to one another at an earlier point in time (corresponding to a value for a correlation measure determined at the earlier point in time) and this correlation is reduced in the current check.

If the change in the deviations in the voltage values or the change in the voltage values of certain correlation values is above a specified tolerance threshold (case distinction 120 in 10 ), a corresponding error report is generated and via a communication link 124 sent, for example to an error reporting point 126 . Alternatively, the error report can also be issued on site. This can cause the affected socket 8th repaired, if necessary even before an actual power failure occurs.

Then, or when differentiating the case 120 No errors were found, a return to step takes place 112 so that the voltage equalization cycle can begin again. For example, the voltage balancing cycle can be carried out at regular intervals of one week.

Claims (15)

Method for assigning phases (L1, L2, L3) in a multi-phase alternating current low-voltage network outlet (2) with several multi-phase connection points (4.1 - 4.N), - for the measured values of an electrical measured variable of the individual phases of a first and the individual phases of a second of the several multi-phase connection points (4.1 - 4.N) are received, - in which a value (Στ) is determined for a correlation measure for several possible candidate phase assignments (I - VI) of the individual phases of the first multi-phase connection point to the individual phases of the second multi-phase connection point , where the value (Στ) for the correlation measure is determined in each case as a function of the received measured values of the electrical measured variable, and - in which, depending on the determined values (Στ) for the correlation measure, a candidate phase assignment from the multiple candidate phase assignments (I - VI) is selected, characterized in - that the phases of the multi-phase connection points (4.1 - 4.N) of the polyphase alternating current low-voltage network outlet (2) are assigned by the individual phases of adjacent polyphase connection points in the polyphase alternating current low-voltage network outlet (2) are assigned to one another. Procedure according to Claim 1 , characterized in that the measured values for the electrical measured variable of the individual phases of a multi-phase connection point are each received by a measuring device (10) assigned to this multi-phase connection point. Procedure according to Claim 1 or 2 , characterized in that measured values for the voltage level or for the current strength are received as measured values for an electrical measured variable. Method according to one of the Claims 1 to 3 , characterized in that to determine a value (Στ) for the correlation measure for a candidate phase assignment (I - VI) initially for each phase of the first polyphase connection point, a respective correlation coefficient (τ) is determined as a function of the received measured values of this phase and of the received measured values of the phase of the second polyphase connection point assigned to this phase according to the candidate phase assignment (I - VI) and the value (Στ) for the correlation measure is dependent is determined by the determined correlation coefficient (τ). Method according to one of the Claims 1 to 4th , characterized in that, in order to assign the phases of the first and the second multi-phase connection point, several phase selection cycles are carried out, preferably at regular time intervals, with each phase selection cycle a respective reception of measured values for the electrical measured variable, a respective determination of the values (Στ) for the correlation measure depending on the measured values for the electrical measured variable and a respective selection of a phase assignment (I - VI) depending on the values (Στ) for the correlation measure, and - that after several phase selection cycles have been carried out, a phase assignment (I - VI) from the Phase assignments (I-VI) selected in each phase selection cycles are selected depending on the frequency with which the individual phase assignments have been selected when performing the plurality of phase selection cycles. Method according to one of the Claims 1 to 5 , characterized in that the phases of the first, the second and a third polyphase connection point are assigned by determining a phase assignment of the individual phases of the first and second polyphase connection point and a phase assignment of the second and the third or the first and the third polyphase connection point. Method according to one of the Claims 1 to 6th , characterized in that the phases of the multi-phase connection points (4.1 - 4.N) of the multi-phase alternating current low-voltage network output (2) are assigned by starting from a last multi-phase connection point (4.N) in the multi-phase alternating current low-voltage network output, the individual phases of adjacent multi-phase connection points in the multi-phase alternating current -Low voltage network output (2) can be assigned to each other. Procedure for selecting a phase (L1, L2, L3) of a multi-phase connection point (4.1 - 4.N) in a multi-phase alternating current low-voltage network outlet (2) for connecting an energy consumer or an energy feeder, - in which location information about the location of the planned connection is received, - in which, depending on the received location information, an associated multi-phase alternating current low-voltage network outlet (2) and an associated multi-phase connection point (4.1 - 4.N) are selected in the multi-phase alternating current low-voltage network outlet (2), - in which information about the phase (L1, L2, L3) to be selected in the selected multi-phase alternating current low-voltage network outlet (2) for an energy consumer or an energy supplier, as well as information about the phase assignment (I - VI) at the selected multi-phase connection point (4.1 - 4.N) and - in which one on the retrieved information about the phase (L1, L2, L3) to be selected in the selected multi-phase alternating current low-voltage network outlet (2) for an energy consumer or an energy supplier and on the retrieved information about the phase assignment (I - VI) on the selected multiphase connection point (4.1 - 4.N) based message is generated and sent. Procedure according to Claim 8 , characterized in that a previously provided information about the phase assignment (I - VI) at the selected multi-phase connection point (4.1 - 4.N) is retrieved, the information about the phase assignment (I - VI) at the selected multi-phase connection point (4.1 - 4 .N) is previously provided by the phase assignment (I - VI) by means of a method according to one of the Claims 1 to 7th and the information about the phase assignment (I - VI) at the selected multi-phase connection point (4.1 - 4.N) is generated depending on the phase assignment (I - VI) determined with the method. Procedure according to Claim 8 or 9 , characterized in that the provision of the information about the phase assignment (I - VI) at the selected multi-phase connection point (4.1 - 4.N) is repeated at predetermined time intervals. Method according to one of the Claims 8 to 10 characterized in that location information transmitted by a mobile device (62), in particular a smartphone, is received as location information and the generated message is sent to the mobile device (62). Method for determining a fault in a multi-phase alternating current low-voltage network output (2), - in which for a first and a second multi-phase connection point (4.1 - 4.N) in a multi-phase alternating current low-voltage network output (2) information about the phase assignment (I - VI) of the respective multi-phase connection point (4.1 - 4.N) is retrieved, - in which the individual phases of the first multi-phase connection point are assigned to the individual phases of the second multi-phase connection point based on the retrieved information about the respective phase assignment (I - VI) and - in which several voltage balancing cycles are carried out are received, preferably at regular time intervals, with each voltage adjustment cycle - values for the voltage level of the individual phases of the first and second polyphase connection point are received, - the received values for the voltage level of the individual phases of the first polyphase connection point with the received Values for the voltage level of the respectively assigned phases of the second multi-phase connection point are adjusted and - depending on the result of the adjustment, it is determined whether there is an error at the first or second multi-phase connection point, an error message being output or sent when an error is determined. Procedure according to Claim 12 , characterized in that a previously provided information about the respective phase assignment (I - VI) is retrieved at the first and the second multi-phase connection point (4.1 - 4.N), the information about the respective phase assignment (I - VI) at the first and the second multi-phase connection point is previously provided by the phase assignment by means of a method according to one of the Claims 1 to 7th determined and the information about the respective phase assignment (I - VI) at the first and the second multi-phase connection point (4.1 - 4.N) is generated depending on the respective phase assignment determined with the method. A system comprising a server (60) which is set up to perform a method according to one of the Claims 1 to 13th to execute. System according to Claim 14 , characterized in that the server (60) has communication connections to a plurality of measuring devices (10), the individual measuring devices (10) each being assigned to a multi-phase connection point (4.1-4N) in a multi-phase alternating current low-voltage network outlet (2).

Images