WO2023001543A1

WO2023001543A1 - Device and method for allocating a phase connection of an electric device to a phase conductor connected thereto

Info

Publication number: WO2023001543A1
Application number: PCT/EP2022/068572
Authority: WO
Inventors: Thorsten Buelo; Rickard NEMETH; Mathias Buenemann
Original assignee: Sma Solar Technology Ag
Priority date: 2021-07-23
Filing date: 2022-07-05
Publication date: 2023-01-26
Also published as: DE102021119207B4; DE102021119207A1

Abstract

The invention relates to a method for identifying an allocation of at least one phase connection (R, S, T) of an electric device (2a-2e) to one or more phase conductors (L1, L2, L3) of an electric distributing grid (22) to which the device (2a-2e) is connected, having the steps of: - detecting voltage fluctuations in the electric distributing grid (22) by detecting a time curve of a conductor voltage (UL1(t), UL2(t), UL3(t)) on each phase conductor (L1, L2, L3) of the electric distributing grid (22) and a time curve of a connection voltage (UR(t), US(t), UT(t)) which is being applied to the at least one phase connection (R, S, T) of the device (2a-2e), wherein the conductor voltages (UL1(t), UL2(t), UL3(t)) have voltage fluctuations which can vary from one another with respect to one another when a change in one or more of the conductor voltages (UL1(t), UL2(t), UL3(t)) is eliminated by the device (2a-2e) itself or by a separate signal generator, - comparing the voltage fluctuations on the phase connection (R, S, T) of the device (2a-2e) with those of each phase conductor (L1, L2, L3), a deviation being quantitatively detected between the time curve of the connection voltage (UR(t), US(t), UT(t)) which has been detected on the phase connection (R, S, T) of the device (2a-2d) and each of the time curves of the conductor voltages (UL1(t), UL2(t), UL3(t)) which have been detected on the phase conductors (L1, L2, L3) with respect to a property of the time curves, and - identifying the allocation of the phase connection (R, S, T) to the phase conductor (L1, L2, L3) connected thereto by determining the combination of the phase connection (R, S, T) and one of the phase conductors (L1, L2, L3) with which the deviation between the time curve of the connection voltage (UR(t), US(t), UT(t)) detected on the phase connection (R, S, T) and the time curve of the conductor voltage (UL1(t), UL2(t), UL3(t)) detected on the respective phase conductor (L1, L2, L3) is minimal with respect to the property of the time curves. The invention additionally relates to a device which is suitable for and which is designed to carry out the method.

Description

DEVICE AND METHOD FOR ASSIGNING A PHASE CONNECTION OF AN ELECTRICAL APPLIANCE TO A PHASE CONDUCTOR CONNECTED TO IT

Technical field of the invention

The application relates to a method for identifying an assignment of at least one phase connection of an electrical device to one of several phase conductors of a multi-phase AC voltage network, which is connected to the at least one phase connection. In this case, the method is also suitable for identifying an assignment of a plurality of phase connections of an electrical device to the respective phase conductors of a multi-phase AC voltage network connected thereto. The application also relates to a device set up for carrying out the method.

State of the art

Electrical energy is transported from energy generation units to energy consumers by means of a nationwide energy supply network. The energy is transported in a multi-phase AC voltage network via several phase conductors - usually two or three phase conductors and one neutral conductor. In addition, a ground potential conductor is usually provided for protection purposes. A consumer unit, e.g. a building or a factory, can contain a large number of electrical devices that are connected to a locally limited area of the power supply network (hereinafter also referred to as the electrical distribution network), which in turn is connected to the rest of the power supply network via a network connection point. In order not to overload individual phase conductors at the expense of others, it is generally desirable for a power flow within the electrical distribution network, as well as within the power supply network, to be divided as evenly as possible between the multiple phase conductors. On the one hand, this is achieved in that single-phase devices are distributed as evenly as possible to the available phase conductors when they are first connected to the electrical distribution network in relation to the total power of the devices. In addition, information about which of the single-phase devices is connected to a common phase conductor is also desirable are. Even with multi-phase devices, it is desirable to also connect each of the phase connections to that of the phase conductors for which it is intended. At a minimum, knowledge is desired as to which of the phase terminals of the devices are each connected to the same one of the phase conductors. This applies in particular if the multi-phase devices are to be deliberately operated under a predefined unbalanced load.

Although the individual phase conductors of the electrical distribution network can be marked with different colors to distinguish them, the use of the correct colored marking is not always guaranteed, for example because a phase conductor with the correct color is not available when wiring the consumer unit and instead a phase conductor with a different but available color scheme is used. A method for reliably identifying an assignment of phase connections to phase conductors of a power supply network is therefore required.

Document EP 2204658 A1 discloses a multi-phase electric power distribution network with a substation, a signal generator and a signal discriminator. A different signal is provided via the signal generator on each of a plurality of phases leaving the substation. The signal discriminator is used to detect each of the different signals at a consumer of electrical energy. By providing the different signal on each of the phases, their identification can be guaranteed. However, this requires a separate signal generator.

The document WO 2020/064169 A1 describes a method for identifying an assignment of phase lines of an electrical distribution network to connections of an electrical device capable of handling unbalanced loads, which is connected to a plurality of phase lines of the electrical distribution network. In the method, setpoint parameters assigned to an unbalanced load profile are set at the connections of the electrical device. A measurement parameter, in particular in the form of a time profile, is detected on each of the phase lines. The detected measurement parameters are compared with the target parameters of the unbalanced load profile. The assignment of the phase lines to the respective connections of the device is then identified on the basis of the comparison. In this case, although no separate signal generator is required, an electrical device capable of skewing loads is required. The method cannot be used for multi-phase devices that cannot be operated with an off-balance load capability.

Document US 2014/0167735 A1 discloses a method for determining a phase conductor with which electrical power is supplied to a node of a network. In doing so, a voltage variation of the electrical power supplied to a subset of nodes is identified, the subset of nodes being associated with a known phase conductor. Furthermore, a variation in the voltage of the electrical power received by a particular node is identified. The phase conductor associated with the particular node is determined by correlating the identified voltage variation in electrical power supplied to the subset of nodes associated with the known phase conductor with the identified voltage variation in electrical power that is received from the particular node.

object of the invention

The invention is based on the object of specifying a method for identifying an assignment of at least one phase connection of an electrical device to one of several phase conductors of a multi-phase AC voltage network, which is connected to the at least one phase connection. In particular, it should be possible to use the method to identify which phase connections of a large number of devices are each connected to the same phase conductor. The method should be as simple and inexpensive to implement as possible. Carrying out the method should neither require a separate signal generator nor an electrical device capable of skewing loads. In concrete terms, the method should also be able to be used when not all devices are multi-phase, but rather individual devices of the group are only single-phase. It is also the object of the invention to specify a device suitable for carrying out the method.

solution

The object of specifying a method of the type mentioned at the outset is solved by a method having the features of independent claim 1 . The task of specifying a device for carrying out the method is achieved by a Object with the features of independent claim 12 solved. Advantageous embodiments of the method are specified in claims 2 to 11, advantageous embodiments of the device are specified in claims 13 to 17.

Description of the invention

A method for identifying an assignment of at least one phase connection of an electrical device to one of several phase conductors of an electrical distribution network to which the device, in particular the at least one phase connection of the device, is connected, has the following steps:

Detection of voltage fluctuations in the electrical distribution network by detecting a time profile of a conductor voltage on each of the phase conductors of the electrical distribution network on the one hand and a time profile of a connection voltage that is present at the at least one phase connection of the electrical device on the other hand, the conductor voltages have voltage fluctuations that can be distinguished from one another in relation to one another, even if the line voltages cannot be changed by the device itself or by a separate signal generator,

Comparing the voltage variation at the phase terminal of the appliance with that of each phase conductor through a comparison of the respective time histories, a deviation between the timing of the terminal voltage detected at the phase terminal of the electrical appliance and each of the time histories of the conductor voltages that were detected at the phase conductors is quantified with respect to a property of the time courses.

Identification of the assignment of the at least one phase connection to the phase conductor connected to it by determining that combination between the phase connection and one of the phase conductors in which the deviation between the time profile of the connection voltage detected at the phase connection and the time profile of the conductor voltage detected at the respective phase conductor Tension related to the property of time courses is minimal.

The invention uses the effect that when a phase conductor of the electrical distribution network is connected to a phase connection of the electrical device, voltage fluctuations on this phase conductor, i.e. fluctuations in the conductor voltage, in at least a similar form and expression Voltage fluctuations, i.e. fluctuations in the connection voltage, can be found at the associated phase connection. In the case of several phase conductors and several phase connections, the phase voltages relative to one another also exhibit voltage fluctuations that can be distinguished from one another if a change in one or more of the phase voltages caused by the device itself or by a separate signal generator is ruled out or does not exist. The voltage fluctuations are in fact already existing voltage fluctuations z. B. generated by devices additionally connected to the distribution network during their normal operation and/or transmitted to the phase conductors of the distribution network via the network connection point. In any case, the voltage fluctuations are not explicitly applied to the phase conductors for the purpose of making the phase conductors distinguishable from one another. Rather, they are already present in normal operation on the phase conductors in a more or less distinguishable form.

In this way, the method enables one or more phase connections of devices to be assigned to the respectively connected phase conductor of the distribution network without necessarily marking the conductor voltages and/or the connection voltages in an identifiable manner using the device itself or using a separate signal generator and/or or have to change. By carrying out the method in the manner described, the phase conductors and thus also the phase connections connected thereto can already be distinguished from one another without an additional marking applied merely for the purpose of distinguishability.

The property of the time curves can be the detected voltages themselves. Specifically, the property can be, for example, effective values of the AC voltages present on the phase conductors, which can optionally also be averaged over small periods of time within the respective time curves. However, a property can also include that the respective course of time runs through a calculation algorithm beforehand and the result of the calculation algorithm represents the property. Thus e.g. For example, a change over time in the respectively detected voltages or the corresponding effective values can also be compared with one another. The device can be a device which is designed to generate a unidirectional flow of power from the distribution network in the direction of the device during operation, ie to operate as an energy consumer with regard to the distribution network. For this purpose, the device can be connected to an energy sink or comprise one. Alternatively, it is also possible for the device to be designed to generate a unidirectional flow of power from the device in the direction of the distribution network during operation, ie to operate as an energy generator in relation to the distribution network. For this purpose the device can be connected to a power source or can comprise a power source. In addition, it is also possible that the device is designed to generate a bidirectional power flow between the distribution network and the device during its operation. In this case, the device can therefore operate as an energy consumer in relation to the distribution network in one period and as an energy producer in another period. For this purpose, the device can be connected to an energy store or contain one.

The method offers the advantage that it is not necessary for the device itself or a separate signal generator to modify the line voltages and/or the terminal voltages in a characteristic manner in order to make them distinguishable. On the contrary, this can be omitted since the voltage fluctuations of the phase conductors that are present anyway are sufficiently distinguishable and can be used as markers for the corresponding phase conductor and the phase connection connected to it—or in the case of several devices: the phase connections connected to it.

In the method, a voltage fluctuation (several voltage fluctuations) is detected in the electrical distribution network, which is at least largely unknown (unknown) in particular in its form and/or in its amplitude before its measurement (before the respective measurements). Rather, the voltage fluctuation only becomes known through its measurement (the voltage fluctuations only become known through their respective measurements). This distinguishes the method from another known method, in which a predefined voltage fluctuation is impressed on a phase conductor (in which predefined voltage fluctuations are impressed on several phase conductors), the shape and/or amplitude of which is already known before it is measured (already before it is measured). respective measurements), in particular even before they are imprinted (before their respective imprints) is at least largely known (are at least largely known). The method offers the advantage that the assignment of a phase conductor to a phase connection can be determined based on a voltage fluctuation that is present in the electrical distribution network anyway. The voltage fluctuations that are present anyway arise as a result of the normal operation of a total of energy consumers, energy producers and/or energy stores that are connected to the different phase conductors of the distribution network and/or the energy supply network connected thereto. The voltage fluctuations that are already present on the phase conductors usually do not otherwise receive any special attention, but are often even undesirable, but cannot be completely avoided. In the case of the invention, on the other hand, use is now made of the fact that the voltage fluctuation, which is present anyway, is usually different from phase conductor to phase conductor and, as a result, forms a characteristic marking of each phase conductor. The phase conductors can therefore be distinguished from one another via the individually different voltage fluctuations. The voltage fluctuations that are present anyway are also transmitted in their respective form to the phase connections of the device connected to the phase conductors or to the phase connection of the device connected to one of the phase conductors. The method now detects the voltage fluctuations of the phase conductors by detecting the time profiles of the conductor voltages and the voltage fluctuations of the phase connection or phase connections by detecting the time profiles of the connection voltage or the connection voltages. By comparing the time curve of the connection voltage or one of the connection voltages with the time curves of all existing conductor voltages, that combination of phase connection and phase conductor can then be determined in which the

Voltage fluctuations, in particular whose time profiles match best. A quality of agreement of the

Voltage fluctuations are quantified for each combination of phase connection and phase conductor by a deviation between the time history of the connection voltage detected at the phase connection and the time history of the conductor voltage detected at the respective phase conductor in relation to a Property of the time courses is determined quantitatively. The combination with the best correspondence between the voltage fluctuations is that combination of phase conductor and phase connection whose deviation in relation to the property of the time curves is minimal. For the method, it is not necessary for the form and/or amplitude of the voltage fluctuations that are present in any case to be known in advance. It is also not necessary to explicitly impose an electrical signature that characterizes the phase conductors and/or the phase connections, which makes them distinguishable from one another, which z. B. could be done via a separate signal generator or a crooked load capable device. Rather, the voltage fluctuations that are present anyway represent a marking of the phase conductors assigned to them and the phase connections electrically connected thereto due to their individual character. As a result, the method can be carried out more cheaply and efficiently and the associated device can be designed less complex. The method can also be used when the electrical device assigned to the phase connections is not able to carry a load at an angle.

Advantageous refinements of the invention are specified in the following description and the dependent claims, the features of which can be used individually and in any combination with one another.

In one embodiment, the electrical device has one, in particular exactly one, phase connection and a neutral conductor connection. The method thus makes it possible to determine to which phase conductor of the multi-phase distribution network the phase connection of the device is connected.

In an alternative embodiment, however, the electrical device has at least two phase connections, in particular three phase connections. The device can also have a neutral conductor connection, but this is not absolutely necessary. The detection of the time profile of the connection voltage (ÜR(t), Us(t), Ur(t)) and the comparison of the voltage fluctuation at one of the phase connections of the device with those of each phase conductor is carried out in this embodiment of the method for all phase connections of the electrical device carried out. In this case, the method can be used to determine to which phase conductor each of the phase terminals of the device is connected. The neutral conductor connection is present on the electrical device in particular if the device is designed as a device capable of skewing loads. In the event that the electrical device is designed as a device that cannot be loaded at an angle, it is possible that the device does not have a neutral conductor connection, or that a neutral conductor connection is present but is not energized during operation of the device, but for example serves as a reference potential for voltage measurements.

In one embodiment, the electrical device is part of a group with a plurality of electrical devices that are connected together to the electrical distribution network and are connected to an optionally higher-level power supply network via a common network connection point. In this embodiment, the method is performed for each device in the group. The method thus makes it possible to determine to which phase conductor each of the phase connections of each device in the group is connected. This embodiment of the method can also be used to determine which phase connection of each device within the group is connected to the same one of the phase conductors.

In one embodiment of the method, a device in the group with a number of phase connections that corresponds to the number of phase conductors in the electrical distribution network is determined as the reference device, and the time profile of the conductor voltages on each of the phase conductors in the electrical distribution network is detected by the reference device. The assignment of the phase connections currently present on the reference device to the phase conductors respectively connected to them can be defined as a reference. For example, in a three-phase arrangement in which the reference device has the three phase connections R, S, T and in which there are a total of three phase conductors within the distribution network, it can be defined that the phase conductor that is currently connected to the phase connection R of the device also corresponds to the phase conductor L1, at least while the method is being carried out, regardless of whether it is actually the phase conductor L1 or not. The same applies accordingly to the phase connection S and the phase conductor connected to it, which then corresponds to the phase conductor L2 at least during the process, and also to the phase connection T and the phase conductor currently connected to it, which then represents the phase conductor L3 at least during the process. For all further devices, the assignment of the phase connection or the phase connections to the phase conductor connected thereto or to the phase conductors respectively connected thereto relative to the assignment defined on the reference device is identified. This is possible because it is often sufficient to determine which phase connections of all devices within a group are each connected to the same phase conductor, regardless of whether the phase conductor is actually a specific one of the phase conductors L1, L2, L3 or Not. The above also applies analogously to an arrangement with a different number of phase conductors, for example for an arrangement with two or more than three phase conductors.

As an alternative to the multi-phase reference device, the time profile of the phase conductor voltages on each of the phase conductors can also be detected using a large number of single-phase devices in a group. In concrete terms, the group can include a large number of devices that have one, in particular precisely one, phase connection and one neutral conductor connection, with the phase connections of the single-phase devices each being connected to different phase conductors in such a way that each phase conductor is connected to at least one phase connection. In such an arrangement, the detection of the time profiles of all connection voltages of the single-phase devices of the group also represents the detection of the time profiles of the conductor voltages on each of the phase conductors of the electrical distribution network. In other words, the time profile of the conductor voltage on each of the phase conductors is detected here by the large number of single-phase devices. The identification of the assignment of the phase connection of the devices to the phase conductor connected to it, if necessary also the assignment of the single-phase devices to each other, which are connected to each other via the same phase conductor, can be done by clustering the devices among themselves, with the clustering depending on the is determined for each combination of two devices of the plurality of calculated deviations. This shows, for example, that devices whose phase connections are connected to one another via the same phase conductor exhibit a particularly small deviation. These deviations are particularly small compared to the deviations of those devices whose phase connections are connected to different phase conductors. In one embodiment of the method, the time profile of the conductor voltage on the phase conductors of the electrical distribution network, in particular on each of the phase conductors of the electrical distribution network, and/or the time profile of the connection voltage on the phase connections of the electrical device, in particular on each of the phase connections of the electrical device, can be carried out via several separately available measuring units that are electrically connected to the distribution network or to the phase connections. In one embodiment of the method, the time profile of the conductor voltage on the phase conductors of the electrical distribution network, in particular each of the phase conductors of the electrical distribution network, and/or the time profile of the connection voltage on the phase connections of the electrical device, in particular on each of the phase connections, is detected of the electrical device, but carried out via a measuring unit present in the electrical device. This is particularly advantageous when the corresponding electrical device already includes a corresponding measuring unit for its normal operation, which can then be used as a measuring unit for detecting the voltage curves of the connection voltages. As a result, the use of additional hardware that would otherwise be required can be reduced. Specifically, for example, the reference device mentioned above can contain both the first measuring unit and the second measuring unit. It is possible that the reference device contains the hardware of only one measuring unit, but this hardware represents both the first measuring unit and the second measuring unit. This results from the fact that the assignment of the phase conductors with the associated phase connections can be defined for the reference device.

In one embodiment of the method, the deviation in relation to the property of the time courses between the time course of the terminal voltage at each of the phase terminals and the phase voltage at each of the phase conductors is quantitatively determined by means of a calculation of least square sums. The calculation of the least squares sums can e.g. B. using the root mean square method.

The property of the time curves can be the detected voltage values per se. In this case, the property can also include an amplitude or an effective value of the respective voltage present as an alternating voltage. However, a property can also include that the passage of time previously calculation algorithm and the result of the calculation algorithm represents the property. It is then also possible for a change over time in the respectively detected voltages to be compared with one another. In one embodiment of the method, the property with respect to which the quantitative determination of the deviation between the time curves takes place can include a change in the terminal voltages and the conductor voltages over time. When changing over time, it can be z. B. be the gradient of the detected time curves of the voltages. Other properties of the time curves of the recorded voltages can also be used for the method. It is also possible to use generic machine learning methods for the method. The properties for the feature extraction, which are used for the method, can be integrated into the algorithm, for example when training an artificial neural network (ANN) or the like.

In one embodiment of the method, a mean value over the time changes in the line voltages and/or an average over the time changes in the connection voltages can also be taken into account in the quantitative determination of the deviation. In this case, the mean value preferably corresponds to the arithmetic mean value of the change over time in the three conductor voltages and/or the three connection voltages. The consideration of the mean value can e.g. This can be done, for example, by subtracting the mean value of the change over time in the three connection voltages of a three-phase device and the mean value of the change in the connection voltages of the reference device over time in the case of single-phase devices - this then corresponds to the mean value of the change over time in the conductor Voltages - is subtracted from the phase under test. As a result, effects which cause an approximately equally large temporal change in the conductor voltages on all phase conductors and which can cover up the voltage fluctuations that are otherwise present within the phase conductors can be at least partially compensated. For example, a deliberately brought about change in a transformation ratio of a transformer at the grid connection point or the voltage fluctuation caused thereby on all phase conductors can be at least partially compensated. In summary, this can significantly increase the accuracy of the method. In one embodiment of the method, values of the connection voltages and/or values of the line voltages are communicated to a server and evaluated by an evaluation unit in the server. Functions and data can be made available on the server, which a user can access via a portal.

The advantages already explained in connection with the method result in a device designed for carrying out the method.

Such a device for identifying an assignment of at least one phase connection of an electrical device to one of several phase conductors of an electrical distribution network has the following: a first measuring unit for detecting a time profile of a conductor voltage on each of the phase conductors of the electrical distribution network, a second measuring unit for detecting a Time profile of a connection voltage at one or more of the phase connections of the electrical device, an evaluation unit for comparing the time profile of the connection voltage at one or more of the phase connections of the device with those time profiles that are assigned to the conductor voltages of the phase conductors, and for identifying an assignment of the one phase connection or each of the phase connections to the phase conductor respectively connected thereto as a function of the comparison.

The first measuring unit can be designed as a measuring unit that is independent of the devices. Specifically, the first measuring unit can be designed as a separate measuring unit. This can e.g. B. be advantageous if the designation of the phase conductors, whose voltage fluctuations are measured by the first measuring unit, is specified, is to be retained and is to serve as a reference value for the phase connections of the devices. As an alternative to this, however, the first measuring unit can also be a component of one of the devices, in particular the reference device.

In one embodiment, the device has a group with two or more electrical devices, each of which is assigned a second measuring unit are connected to the electrical distribution grid and connected to the power supply grid via a common grid connection point. The first measuring unit is preferably part of a first device in the group and/or the second measuring units are each part of an electrical device in the group. The first device can be designed as a multi-phase device and have a number of phase connections that corresponds to the number of phase conductors present in the distribution network. In this case, the first device can serve as the reference device of the group.

In one embodiment of the device, an electrical device, several electrical devices and/or all electrical devices are connected to one another, to the evaluation unit and/or to a server in terms of data technology, ie for communication in particular via the Internet. Functions and data can be made available on the server, which a user can access via a portal. The evaluation unit can be part of one or more of the devices or part of the server.

Various applications of the method and the device are described below, which can advantageously run using an evaluation unit arranged on a server.

The method and the device can be used to determine to which phase conductor a phase connection of a device is actually connected. In the case of a system with a number of electrical devices which are connected to a common distribution network, the method can also be used to limit unbalanced loads and/or provide overload protection. The method can also support balancing measures that are carried out by an operator of the power supply network.

A further application of the method can be used to separate or also to allocate installations that are geographically or network topologically remote. For example, by comparing the voltage fluctuations in the conductor voltages of two systems or their different distribution networks, the method can identify whether the two systems or their distribution networks are electrically “close” to one another or “distant” from one another. In concrete terms, a deviation in the line voltages of the two distribution grids can be measured quantitatively to be determined. When determining the distance between the two installations, the effect is then exploited that the geographic or network topological distance between the two installations usually increases with increasing deviation of the conductor voltages from one another. In other words, the quantitative deviation determined in this way can be viewed as a measure of the geographic or network topological distance between the two systems.

Brief description of the figures

The invention is illustrated below with the aid of figures. From these show

1a schematically shows a first embodiment of a device for identifying an assignment of at least one phase connection to one of a plurality of phase conductors;

1b schematically shows a second embodiment of a device for identifying an assignment of at least one phase connection to one of a plurality of phase conductors;

2 schematically shows a third embodiment of a device for identifying an assignment of at least one phase connection to one of a plurality of phase conductors;

FIG. 3a shows exemplary time curves of connection voltages; FIG.

FIG. 3b exemplary time curves of connection voltages; FIG.

3c shows exemplary time characteristics of terminal voltages; such as

4 shows a flow chart of a method for identifying an assignment of each of the phase connections of a number of devices to one of a number of phase conductors.

In the figures, identical or similar elements are denoted by the same reference symbols. fiqure description

A first embodiment of a device 1 for identifying an assignment of a phase connection R of an electrical device 2e to one of a plurality of phase conductors L1, L2, L3 of an electrical distribution network 22 is shown schematically in FIG. 1a. By way of example, the electrical device 2e is designed as a single-phase photovoltaic (PV) inverter and has the phase connection R and a neutral conductor connection NG on an AC side. On a DC side, the device 2e is connected to a photovoltaic (PV) generator 4 as a power source.

The electrical distribution network 22 has the phase conductors L1 , L2 , L3 and a neutral conductor N and is connected to a higher-level energy supply network 20 via a network connection point 21 . The energy supply network 20 is usually a multi-phase AC voltage network, which is shown in FIG. 1a as an example as a three-phase AC voltage network. The network connection point 21 is a connection point between the energy supply network 20 of an energy supply company and the lines of the locally limited electrical distribution network 22, which z. B. can be assigned to a building, a commercial enterprise or a factory. The network connection point 21 can have additional components that are not shown explicitly in FIG. For example, it may include electrical fuses to prevent an overcurrent condition or a transformer designed to transform an AC voltage present within the power grid 20 into an AC voltage within the distribution grid 22 .

The device 1 has a first measuring unit 12 for detecting a time profile of conductor voltages Uu(t), Ui_2(t), Ui_3(t) on the phase conductors L1, L2, L3 of the electrical distribution network 22. The device 1 also has a second measuring unit 13 for detecting a time profile of the connection voltage ÜR(t) at the phase connection R of the electrical device 2e. The device 1 also has an evaluation unit 11, which is connected to the measuring units 12, 13 via a data connection 14—illustrated as a dashed line in FIG. 1a—for control and/or communication. The evaluation unit 11 is set up to compare the time curve of the connection voltage ÜR(t) at the phase connection R of the device 2e with the time curves that correspond to the conductor voltages Uu(t), Ui_2(t), UL3(t) of the phase conductors L1, L2, L3 are assigned. The evaluation unit 11 is further set up, depending on this comparison, to identify the connection of the phase connection R of device 2e to the phase conductor L1, L2, L3 currently connected to it—in FIG. 1a, for example, the phase conductor L3.

In Fig. 1a the first measuring unit 12 is illustrated as a separate measuring unit. This is advantageous if the designation of the phase conductors L1, L2, L3, which are measured directly by the first measuring unit 12, is specified, is to be retained and is to be used as a reference value for the phase connection R of the device 2e.

In Fig. 1b is a second embodiment of a device 1 for identifying an assignment of each of the multiple phase connections R, S, T of an electrical device 2a, and of the phase connection R of the electrical device 2e (see FIG. 1a) to each one of several phase conductors L1, L2, L3 of an electrical distribution network 22 is shown. The electrical device 2a is designed, for example, as a three-phase battery inverter and has the phase connections R, S, T and a neutral conductor connection NG on an AC side. The device 2a is connected to a battery 3 on a DC side.

The device 1 has a first measuring unit 12 for detecting a time profile of conductor voltages Uu(t), Ui_2(t), Ui_3(t) on the phase conductors L1, L2, L3 of the electrical distribution network 22. In addition to the second measuring unit 13 for measuring a time curve at the phase connection R of the device 2e (cf. Fig. 1a), the device 1 has a further second measuring unit 13 which is set up to measure the time curves of the connection voltages UR(t) , Us(t), IIt(ί) at the phase connections R, S, T of the device 2a. The device 1 also has an evaluation unit 11 which is connected to the measuring units 12 , 13 via a data connection 14 . The evaluation unit 11 is set up to compare the time curve of the connection voltage UR(t) at the phase connection R of the device 2e with the time curves of the conductor voltages Uu(t), Ui_2(t), Ui_3(t) of the phase conductors L1, L2, L3 are assigned. The evaluation unit 11 is also set up to identify the connection of the phase connection R of the device 2e to the phase conductor L3 as a function of this comparison. The evaluation unit 11 is also set up to compare the time profiles of the connection voltages UR(t), Us(t), Ur(t) at the phase connections R, S, T of the device 2a with the time profiles that correspond to the line voltages Uu (t), Ui_2(t), Ui_3(t) the Phase conductors L1, L2, L3 are assigned. The evaluation unit 11 is also set up to identify the connection between the phase connections R, S, T of device 2a and the phase conductors L1, L2, L3 as a function of this comparison.

The first measuring unit 12 as a separate measuring unit is advantageous, for example, when the designation of the phase conductors L1, L2, L3, which are measured directly by the first measuring unit 12, is specified and is to be retained and used as a reference value for the phase connections R, S, T of the devices 2a, 2e should serve.

2 shows a third embodiment of a device 1 for identifying an assignment of each of the phase connections R, S, T of electrical devices 2a-2d to one of a plurality of phase conductors L1, L2, L3 of an electrical distribution network 22. By way of example, the electrical device 2a in FIG. 2 is designed as a three-phase battery inverter and has the phase connections R, S, T and the neutral conductor connection NG on the AC side. The device 2a is connected to the battery 3 on the DC side. The electrical device 2b is designed as a three-phase photovoltaic (PV) inverter and has the phase connections R, S, T and a neutral conductor connection NG on an AC side. The device 2b is connected to a photovoltaic (PV) generator 4 on a DC side. The electrical device 2c is designed as a three-phase hybrid inverter and has the phase connections R, S, T and a neutral conductor connection NG on its AC side. The device 2c is connected to a photovoltaic (PV) generator 4 and a battery 3 on its DC side. The electrical device 2d is designed as a three-phase frequency converter and has the phase connections R, S, T and a neutral conductor connection NG on a first AC voltage side. The device 2d is connected to an electric motor 5 on its other side.

The devices 2a, 2b, 2c, 2d each have a measuring unit (not shown) for voltage measurement. These measuring units each serve as second measuring units 13, which are set up to measure the time curves of the corresponding connection voltages UR(t), Us(t), IIt(ί) at the phase connections R, S, T of the devices 2a, 2b, 2c, 2d to measure. The function of a first measuring unit 12 for detecting a time profile of conductor voltages Uu(t), Ui_2(t), Ui_3(t) on the phase conductors L1, L2, L3 of the electrical distribution network 22 is performed by one of these units of measurement perceived. It is part of one of the devices 2a, 2b, 2c, 2d, specifically the device that is defined as the so-called reference device. This definition is flexible in the embodiment in Fig. 2, it being possible to define each of the devices 2a, 2b, 2c, 2d as a reference device, because the number of phase connections of the devices 2a, 2b, 2c, 2d for all devices with the number of phase conductors L1, L2, L3 within the distribution network 22 matches.

The device 1 also has an evaluation unit 11 which is connected to the measuring units 12, 13 via a data connection. The evaluation unit 11 is set up to compare the time profiles of the connection voltages UR(t), Us(t), IIt(ί) at the phase connections R, S, T of each of the devices 2a, 2b, 2c, 2d with the time profiles which are assigned to the conductor voltages Uu(t), Ui_2(t), Ui_3(t) of the phase conductors L1, L2, L3. The evaluation unit 11 is also set up to identify the connection of the phase connections R, S, T of each of the devices 2a, 2b, 2c, 2d to the phase conductors L1, L2, L3 as a function of this comparison. The evaluation unit 11 can also assign those devices that have the same phase assignment to a cluster. In the example shown z. B. the devices 2a and 2d belong to the same cluster because they have the same assignment between their phase terminals R, S, T and the corresponding phase conductors L1, L2, L3. The devices 2b and 2c would belong to a different cluster because they also have the same allocation between their phase connections R, S, T and the corresponding phase conductors L1, L2, L3.

The electrical devices 2a, 2b and 2c each have a radio interface 6 for data communication. The device 2d has a data connection 14 with the device 2c. This data connection 14 can be wireless or wired. The devices 2c and 2d can be z. B. are spatially close to each other. The devices 2a, 2b, 2c are z. B. connected to the Internet 30 via its radio interface 6 . The device 2d can e.g. B. be connected to the Internet 30 via the data connection 14 and the radio interface 6 of the device 2c. The evaluation unit 11 can be located on a server 31 connected to the devices 2a, 2b, 2c, 2d, for example via the Internet 30. The server 31 can be accessed from a PC 32 and via the Internet 30, e.g. B. via a portal that the server 31 provides.

In the device that serves as a reference device, the first measuring unit 12 can be identical to the second measuring unit 13 . In this case, the Corresponding measuring unit has a double function in that it serves both as the first measuring unit 13 to detect the connection voltages at the phase connections R, S, T of the reference device and - by definition - to assign the phase connections R, S, T of the reference device to the respectively connected phase conductors L1, L2, L3 - to detect the conductor voltages Uu(t), Ui_2(t), Ui_3(t) on the phase conductors L1, L2, L3 defined in this way. This is possible, for example, when it is only important to identify which of the phase connections R, S, T of the devices 2a, 2b, 2c, 2d, 2e is connected to the same one of the phase conductors L1, L2, L3.

FIG. 3a shows exemplary time curves of connection voltages UR(t) of devices 2a, 2b, 2c, 2d from FIG. In devices 2a and 2d, the respective phase connection R is connected to the same phase conductor L3. The time curves UR(t) for devices 2a and 2d are therefore the same. The two curves are superimposed and cannot be distinguished in FIG. 3a. In the same way, the respective phase connection R is connected to the same phase conductor L2 in the devices 2b and 2c. The time curves UR(t) for devices 2b and 2c are therefore the same. The two curves are superimposed and cannot be distinguished in FIG. 3a. When devices are clustered, a curve from FIG. 3a can correspond to a cluster of two devices from FIG. If one of the devices 2a, 2b, 2c, 2d is defined as a reference device, the assignments of the other devices can be determined with knowledge of the time curves of the connection voltages UR(t), Us(t), U-r(t) (cf. Figs. 3b , 3c) are identified in relation to the assignments on the reference device.

FIG. 3b shows exemplary time curves of connection voltages Us(t) of devices 2a, 2b, 2c, 2d from FIG. In devices 2a and 2d, the respective phase connection S is connected to the same phase conductor L2. The time profiles Us(t) for the devices 2a and 2d are therefore the same. The two curves are superimposed and cannot be distinguished in FIG. 3b. In the same way, the respective phase connection S is connected to the same phase conductor L1 in the devices 2b and 2c. The time profiles Us(t) for the devices 2b and 2c are therefore the same. The two curves are superimposed and cannot be distinguished in FIG. 3b. When devices are clustered, a curve from FIG. 3b can correspond to a cluster of two devices from FIG. FIG. 3c shows exemplary time curves of connection voltages IIt(ί) of devices 2a, 2b, 2c, 2d from FIG. In devices 2a and 2d, the respective phase connection T is connected to the same phase conductor L1. The time curves IIt(ί) for devices 2a and 2d are therefore the same. The two curves are superimposed and cannot be distinguished in FIG. 3c. In the same way, the respective phase connection T is connected to the same phase conductor L3 in the devices 2b and 2c. The time curves IIt(ί) for the devices 2b and 2c are therefore the same. The two curves are superimposed and cannot be distinguished in FIG. 3c. When devices are clustered, a curve from FIG. 3c can correspond to a cluster of two devices from FIG.

In summary, it can be determined in this way which phase connections R, S, T of the different devices 2a-2d are each connected to the same one of the phase conductors L1, L2, L3—and also to one another via the phase conductors L1, L2, L3.

FIG. 4 shows a flow chart of a method for identifying an assignment of each of the phase connections R, S, T of several devices to one of several phase conductors L1, L2, L3. After the start in step S1, the connection voltage UR(t), Us(t), IIt(ί) for each phase connection of each device 2a-2e is measured by the respective second measuring units 13 in step S2.

In the case of a separate first measuring unit 12, the conductor voltages Uu(t), Ui_2(t), U L3 (t) for each phase conductor L1, L2, L3 of the electrical distribution network 22 is measured. As an alternative to step 3a, in the absence of a separate first measuring unit 12, one of the devices 2a, 2b, 2c, 2d can be determined as the reference device in step S3b. In this case, each of the conductor voltages Uu(t), Ui_2(t), Ui_3(t) is assigned to one of the detected connection voltages UR(t), Us(t), U-r(t) of the reference device by definition.

In step S4 a combination of device and phase connection R, S, T and phase conductors L1, L2, L3 is selected. For this combination, the time profile at the selected phase connection of the selected device is compared with the time profile of the selected phase conductor in step S5. In step S6, the Comparison evaluated by quantifying a deviation in relation to a property of the time courses, and storing the result. If all combinations of phase connections R, S, T and phase conductors L1, L2, L3 for the selected device have not yet been compared, branch "no" from step S7, then in step S8 the next combination of phase connections R, S, T and phase conductors L1, L2, L3 is selected for the selected device and steps S5 to S7 are run through again. If all combinations are compared with one another, branch "yes" from step S7, then the phase connection R, S, T is assigned to that phase conductor L1, L2, L3 whose combination in step S6 resulted in the smallest deviation.

In step S9 it is checked whether steps S5 to S8 have been carried out for all devices. If this is not the case, branch “no” from step S9, the next device is selected in step S10 and steps S5 to S9 are run through again. If all devices have already been processed, branch "yes" from step S9, the identified association is output in step S11 and the method ends in step S12.

Reference character list

1 device

2a, 2b, 2c, 2d Electrical device

3 battery

4 photovoltaic (PV) generator

5 engine

6 radio interface 11 evaluation unit 12 (first) measuring unit

13 (second) measurement unit

14 data connection

20 power supply network

21 grid connection point

22 distribution network

30 Internet

31 servers

32 computers

R, S, T phase connection NG neutral connection

L1 , L2, L3 phase conductor N neutral conductor

ULI (t), UL2(t), UL3(t) phase voltage ll _R (t), Us(t), U _T (t) connection voltage S1-S12 process step

Claims

patent claims

1. Method for identifying an assignment of at least one phase connection (R, S, T) of an electrical device (2a-2e) to one of several phase conductors (L1, L2, L3) of an electrical distribution network (22) with which the device (2a -2e) is connected, with the steps:

Detection of voltage fluctuations in the electrical distribution network (22) by detecting a time profile of a conductor voltage (Uu(t), Ui_2(t), Ui_3(t)) on each of the phase conductors (L1, L2, L3) of the electrical distribution network ( 22) on the one hand and a detection of a time profile of a connection voltage (UR(t), Us(t), IIt(ί)) which is present at the at least one phase connection (R, S, T) of the device (2a-2e). , on the other hand, wherein the phase-to-phase voltages (ULI (t), Ui_2 (t), UL3 (t)) relative to one another also have voltage fluctuations that can be distinguished from one another if a change in one or more of the phase-to-phase voltages (ULI (t), Ui_2 (t), Ui_3 (t)) is excluded by the device (2a-2e) itself or by a separate signal generator,

Comparison of the voltage variation at the phase connection (R, S, T) of the device (2a-2e) with those of each phase conductor (L1, L2, L3), with a deviation between the time profile of the connection voltage (UR(t), Us( t), U-r(t)) detected at the phase connection (R, S, T) of the device (2a-2d) and each of the time histories of the phase voltages (Uu(t), Ui_2(t), Ui_3 (t)), which were detected on the phase conductors (L1, L2, L3), is quantitatively determined in relation to a property of the time courses,

Identification of the assignment of the phase connection (R, S, T) to the phase conductor (L1, L2, L3) connected to it by determining that combination between the phase connection (R, S, T) and one of the phase conductors (L1, L2, L3), in which the deviation between the time profile of the connection voltage ( U R(t) , Us(t), U-r(t)) detected at the phase connection (R, S, T) and that at the respective phase conductor (L1, L2, L3 ) detected time profile of the conductor voltage (Uu(t), Ui_2(t), Ui_3(t)) is minimal in relation to the property of the time profiles.

2. The method as claimed in claim 1, wherein the device (2e) has one, in particular exactly one, phase connection (R, S, T) and a neutral conductor connection (NG).

3. The method according to claim 1, wherein the device (2a-2d) has at least two phase connections (R, S, T), in particular three phase connections (R, S, T) and optionally a neutral conductor connection (NG), and wherein the detection of the Time course of the connection voltage (UR(t), Us(t), IIt(ί)) and the comparison of the voltage fluctuations at one of the phase connections (R, S, T) of the device (2a-2d) with those of each phase conductor ( L1, L2, L3), for all phase connections (R, S, T) of the device (2a-2d).

4. The method according to any one of the preceding claims, wherein the device (2a-2e) is part of a group with a plurality of devices (2a-2e) which are connected together to the electrical distribution network (22) and via a common network connection point (21). are connected to an energy supply network (20), and wherein the method is carried out for each device (2a-2e) of the group.

5. The method according to claim 4, wherein a device (2a) of the group with a number of phase connections (R, S, T) that corresponds to the number of phase conductors (L1, L2, L3) of the electrical distribution network (22) as a reference device is determined and the detection of the time profile of the conductor voltages (Uu(t), Ui_2(t), Ui_3(t)) on each of the phase conductors (L1, L2, L3) of the electrical distribution network (22) is carried out by the reference device, and wherein for all further devices (2b-2e) the identification of the assignment of the phase connection (R) or the phase connections (R, S, T) to the phase conductor (L1, L2, L3) connected thereto or to the phase conductors ( L1, L2, L3) relative to an assignment defined on the reference device.

6. The method according to claim 4, wherein the group includes a large number of devices (2a-2e) which have one, in particular precisely one, phase connection (R, S, T) and a neutral conductor connection (NG) which are connected to different ones of the phase conductors (L1 , L2, L3) of the distribution network (22) are connected, the detection of the time course of the conductor voltages (Uu (t), Ui_2 (t), Ui_3 (t)) on each of the phase conductors (L1, L2, L3) of electrical distribution network (22) by the multiplicity of single-phase devices (2a - 2e), and the identification of the assignment of the phase connection (R, S, T) of the devices (2a - 2e) to the phase conductor (L1, L2, L3), possibly also the assignment of single-phase devices (2a - 2e) to one another, which are each connected to one another via the same phase conductor (L1, L2, L3), via clustering of the devices (2a - 2e) with one another, with the clustering depending on the for each combination of two devices (2a-2e) of the plurality of calculated deviations is determined.

7. The method according to any one of the preceding claims, wherein the detection of the time profile of the conductor voltage (Uu(t), Ui_2(t), Ui_3(t)) on the phase conductors (L1, L2, L3) of the electrical distribution network (22) and/or the time course of the connection voltage (UR(t), Us(t), IIt(ί)) at the phase connections (R, S, T) of the device (2a-2e) via a voltage in the device (2a- 2e) existing measuring unit (12, 13) is carried out.

8. The method according to any one of the preceding claims, wherein the quantitative determination of the deviation in relation to the property of the time profiles between the time profile of the terminal voltage (UR(t), Us(t), IIt(ί)) at each of the phase terminals ( R, S, T) and the conductor voltage (Uu(t), Ui_2(t), Ui_3(t)) on each of the phase conductors (L1, L2, L3) by means of a least squares sum calculation.

9. The method according to any one of the preceding claims, wherein the property with respect to which the quantitative determination of the deviation between the time curves takes place is a change in the terminal voltages (UR(t), Us(t), U-r(t)) over time. and the conductor voltages (Uu(t), Ui_2(t), Ui_3(t)).

10. The method as claimed in claim 9, wherein the quantitative determination of the deviation also includes an average over the changes over time in the conductor voltages (Uu(t), Ui_2(t), Ui_3(t)) and/or an average over the changes over time of the connection voltages (UR(t), Us(t), U-r(t)) is taken into account.

11. The method according to any one of the preceding claims, wherein values of the connection voltages (UR(t), Us(t), U-r(t)) and/or values of the conductor voltages (Uu(t), Ui_2(t), Ui_3(t)) are communicated to a server (31) and evaluated by an evaluation unit (11) in the server (31).

12. Device (1) for identifying an assignment of at least one

Phase connection (R, S, T) of an electrical device (2a-2e) to one of a plurality of phase conductors (L1, L2, L3) of an electrical distribution network (22) comprising: a first measuring unit (12) for detecting a time profile of a conductor voltage (Uu(t), Ui_2(t), Ui_3(t)) at each of the Phase conductors (L1, L2, L3) of the electrical distribution network (22), a second measuring unit (13) for detecting a time profile of a connection voltage (UR (t), Us (t), IIt (ί)) on one or more of Phase connections (R, S, T) of the device (2a-2e), an evaluation unit (11) to compare the time profile of the connection voltage (UR (t), Us (t), IIt (ί)) on one or the several of the phase connections (R, S, T) of the device (2a-2e) with the time profiles that correspond to the conductor voltages (Uu(t), Ui_2(t), Ui_3(t)) of the phase conductors (L1, L2, L3 ) are assigned, as well as for identifying an assignment of the one phase connection or each of the phase connections (R, S, T) to the phase conductor (L1, L2, L3) respectively connected thereto, depending on the comparison, characterized in that the device (1) is designed and set up for carrying out the method according to one of the preceding claims.

13. Device (1) according to claim 12, wherein the device (1) includes a group with two or more devices (2a-2e), each of which is assigned a second measuring unit (13), the devices (2a-2e) on connected to the electrical distribution network (22) and connected to the power supply network (20) via a common network connection point (21).

14. Device (1) according to claim 13, wherein the first measuring unit (12) is part of a first device (2a) of the group and/or the second measuring units (13) are each part of a device (2b-2e) of the group.

15. Device (1) according to claim 14, wherein the first device (2, 2a) is designed as a multi-phase device and serves as a reference device of the group.

16. Device (1) according to one of claims 12 to 15, wherein a device (2a-2e), several devices (2a-2e), optionally all devices (2a-2e) with each other in terms of data technology, with the evaluation unit (11) and/or or connected to a server (31).

17. Device (1) according to one of claims 12 to 16, wherein the evaluation unit (11) is part of one or more of the devices (2a-2e) or part of the server (31).