Measuring converter for sensing electric current

Abstract

The invention relates to a measuring converter (100) for sensing an electric current flowing through a conductor (300). The measuring converter (100) comprises a current transformer (102) which generates an analogue signal of the current, corresponding to the electric current flowing through the conductor (300). An analogue-digital converter (104) generates a digital signal of the current corresponding to the analogue signal of the current. Furthermore, the measuring converter (100) comprises a network interface (106) and a microcontroller (108) which, on the basis of a digital signal of the current, outputs a data packet according to a communications protocol (160; 165) at the network interface (106). Finally, a power supply (110) of the measuring converter (100) is fed by the network interface (106) and / or the current to be sensed.

Description

[0001] Measuring transducer for measuring electrical current

[0002] The present invention relates to the detection of an electrical current through a conductor for further mechanical processing. For this purpose, a measuring transducer and a system comprising a plurality of such measuring transducers and a central receiving device are disclosed.

[0003] Electrical currents are measured by current transformers, which can be designed as measuring current transformers, for example. Current transformers typically deliver weak analog measurement signals to downstream components, so for their safe and flexible handling, either strict layout and installation space specifications must be adhered to or signal lines must be extensively shielded against interference and crosstalk.

[0004] When transmitting weak analog signals, in addition to the correct detection of the actual signal magnitude, there is also a significant potential for interference, for example, from electromagnetic influences, connecting elements, or similar. These electromagnetic influences, contact resistances, and similar factors can couple interference into the line and thus distort the measured signal. Corresponding shielding measures are generally costly.

[0005] A conventional solution is to digitally convert the analog measurement signals for further processing. The disadvantage of digitally converting analog measurement signals close to the measuring point is the need to provide a dedicated power supply for the digital conversion and possibly additional components, which are dispensable for many measuring converters. For example, a measuring current transformer does not require its own power supply to determine the current value, which can range from a few amperes to several thousand amps.

[0006] The invention is therefore based on the object of providing a measuring converter and a system in which the strict arrangement and installation space requirements of (in particular uninterruptible) current transformers and further components are relaxed, without providing an additional voltage supply (supply) at least for the other components near the measuring point.

[0007] The object is achieved with the features of each of the independent claims. Expedient embodiments and advantageous further developments of the invention are specified in the dependent claims. Embodiments of the invention, which can be optionally combined with one another, are disclosed below with partial reference to the figures. In particular, features mentioned in the context of the device can also be implemented correspondingly in the method, for example by a step of providing the corresponding feature or by a step of executing a function of the device. Furthermore, the device can comprise any feature mentioned in the context of the method and can be designed to execute any step mentioned in the context of the method.

[0008] A first aspect relates to a measuring transducer for detecting an electrical current flowing through a current conductor. The measuring transducer has a current transformer configured to generate an analog current signal corresponding to the electrical current flowing through the current conductor. An analog-to-digital converter of the measuring transducer is configured to generate a digital current signal corresponding to the analog current signal. The measuring transducer further comprises a network interface. A microcontroller of the measuring transducer is configured to output a data packet based on the digital current signal at the network interface according to a communication protocol. The measuring transducer further comprises a power supply for the measuring transducer, which is powered by the network interface and / or the current to be detected.

[0009] The current can be an alternating current. Alternatively or additionally, the current transformer (i.e., a current measuring device) can be designed for uninterrupted current measurement. The current transformer can be arranged to measure the current in such a way that the current transformer does not interrupt the current-carrying conductor, and there is no series connection of the current transformer in the current-carrying conductor. This means that the current transformer can be arranged or can be arranged uninterrupted for current measurement. This enables, for example, the measuring transducer to be retrofitted or used to conduct high currents. For example, the current transformer can be designed to measure the current in a contactless manner (e.g., without contact).

[0010] The conductor can be a busbar, for example, with a rectangular cross-section. The measuring transducer (for example, its housing) can be designed for mechanical connection directly and / or exclusively to the conductor.

[0011] The current analog signal can be proportional or linear to the current flowing in the conductor. For example, the current transformer (CT) can convert the electrical current flowing through the conductor into a signal current proportional to the measured current as the analog signal, or it can generate a measuring voltage proportional to the measured current.

[0012] The current transformer may have a division ratio (e.g. conversion ratio) between the current of the current conductor and the analog signal of the current, for example of 160 to 1 (e.g. 800 A to 5 A).

[0013] The analog-to-digital converter (ADC) can also be referred to as an analog-to-digital converter (A / D converter or ADC, in technical terms also known as "converter"). The generation of the digital signal can also be referred to as converting or converting the analog signal into a current-digital signal.

[0014] The digital signal of a current can also be referred to as a current digital signal or, for short, a current signal. The digital signal of a voltage can also be referred to as a voltage digital signal or, for short, a voltage signal.

[0015] The communication protocol can be digital and / or packet-oriented. Alternatively or additionally, the communication protocol can be designed for the exchange of current measurement results or current-based measurement variables.

[0016] The communication protocol can correspond to a layer of a protocol stack, for example layer 2 or data link layer or layer 3 or network layer.

[0017] The output of a data packet (for example, at least one data packet or a sequence of data packets) according to the communication protocol at the network interface can also be referred to as packet-oriented output or communication.

[0018] The measuring transducer can also be designed to detect an electrical voltage of the current conductor (for example the busbar).

[0019] The measuring converter may further comprise a voltage transformer which is designed to generate an analog voltage signal corresponding to an electrical voltage applied to the current conductor.

[0020] The measuring converter can further comprise another analog-to-digital converter configured to generate a digital voltage signal corresponding to the analog voltage signal. Alternatively or additionally, the aforementioned analog-to-digital converter can further be configured to generate a digital voltage signal corresponding to the analog voltage signal. The microcontroller is configured to output the data packet to the network interface according to the communication protocol based on the digital current signal and the digital voltage signal.

[0021] The voltage transformer (VT) can be a voltage tap, and / or the voltage transformer's division ratio between the conductor voltage and the analog voltage signal can be one (1). For example, several contact pins can be mechanically preloaded on the conductor to tap the (electrical) voltage. The contact pin(s) can also serve as a mechanical connection between the measuring transducer and the conductor.

[0022] Optionally, the same analog-to-digital converter can be designed to alternately generate the digital voltage signal corresponding to the analog voltage signal and the digital current signal corresponding to the analog current signal.

[0023] The microcontroller can be configured to determine a power level based on the digital current signal and the digital voltage signal. The output data packet can indicate the determined power level.

[0024] The data packet may include a digital power signal (power digital signal, or power signal for short). The microcontroller may determine the power signal based on the current signal and the voltage signal.

[0025] The data packet can specify an active power, an apparent power, a reactive power, and / or a phase angle between the current and the voltage. Optionally, the output data packet can also specify the current and / or the voltage.

[0026] A measuring converter can have a bit depth and / or a dynamic range of the digital signal that are independent of the analog signal. The analog-to-digital converter can be designed to generate the digital signal of the current. The analog-to-digital converter generates the digital signal of the current by sampling the analog signal of the current. Alternatively or additionally, the bit depth of the digital signal of the current can be at least 64 bits. The further analog-to-digital converter can be designed to generate the digital signal of the voltage. The further analog-to-digital converter can generate the digital signal of the voltage by sampling the analog signal of the voltage. Alternatively or additionally, the bit depth of the digital signal of the voltage can be at least 64 bits. The data packet can specify the current flowing through the current conductor. Alternatively or additionally, the data packet can specify the voltage present at the current conductor.Alternatively or additionally, the data packet can specify the specific power. The data packet can contain the information in an absolute physical unit.

[0027] Alternatively or additionally, the information in the data package can be independent of the current transformer's division ratio. Alternatively or additionally, the information in the data package can be independent of the voltage transformer's division ratio.

[0028] Digitization, i.e., the mapping of the analog signal to the digital signal, can imply a (for example, time-independent) division ratio of the current transformer and / or the voltage transformer. Alternatively or additionally, the division ratio of the current transformer and / or the voltage transformer can be an operating parameter of the microcontroller and / or specified in the data packet.

[0029] The analog-to-digital converter (and / or optionally the additional analog-to-digital converter) can be arranged in a housing of the current transformer. Alternatively or additionally, the measuring converter can comprise a housing in which the current transformer and at least one of the following features is arranged: the analog-to-digital converter; the additional analog-to-digital converter; the network interface; and the microcontroller.

[0030] The power supply may be configured to electrically supply at least one of the following components: the analog-to-digital converter; the further analog-to-digital converter; the network interface; and the microcontroller.

[0031] The network interface can be connected or connectable to at least two data lines. The power supply can be configured to supply at least one of the aforementioned components with a supply voltage superimposed on the data lines.

[0032] The network interface can be an Ethernet interface. Alternatively or additionally, the electrical supply can be implemented according to Power over Ethernet (PoE), for example, according to the IEEE 802.3 standard. The PoE standard defines various power classes, which can vary between approximately 15 W (IEEE 802.3af, PoE) and up to 100 W (IEEE 802.3bt, PoE++). The measuring converter, or optionally the power supply, can be configured for PoE detection and / or PoE classification, for example, to ensure the permissible supply power and to inform the network about the required power class. After detection and / or classification, the power supply can be activated via the data lines (for example, an Ethernet cable), and the measuring converter receives the required operating power.An internal current regulator in the power supply of the measuring converter can be configured to convert the PoE power supply voltages obtained from the network interface into specific operating voltages required for the other building blocks (i.e., components) of the measuring converter, such as the microcontroller, the current transformer, and the analog-to-digital converter.

[0033] Alternatively or additionally, the power supply of the measuring transducer can be realized by the current to be measured via the current transformer (e.g., in the case of so-called "energy harvesting"). In this approach, the current transformer not only generates a measurement signal for the measuring function, but simultaneously harvests energy from the current flowing through the conductor to be measured to power the electronics of the measuring transducer.

[0034] The current transformer may comprise a small-signal transformer, a measuring current transformer, a Rogowski coil, a direct-imaging current sensor (e.g., a Hall sensor), a zero-flux transformer (e.g., with a compensation winding through which a current signal flows as the analog signal of the current to be detected and is electronically controlled to compensate for a magnetic field generated by the current) and / or an optoelectronic converter.

[0035] The current transformer may comprise a measuring current transformer. The measuring current transformer may be a transformer (preferably with a ferromagnetic core) that detects the current in a circuit (e.g., a shunt of the current conductor) using a primary coil and converts it into an analog current signal in a secondary coil inductively coupled to the primary coil. Alternatively or additionally, the current transformer may comprise a Rogowski coil. The Rogowski coil may comprise a toroidal coil (preferably without a ferromagnetic core, e.g., an air-core coil, a vacuum coil, or a coil encapsulated with a synthetic resin).

[0036] The current transformer can be configured to detect only an alternating current component of the current flowing through the conductor. The current transformer can be configured not to detect any direct current or mixed current. For example, a direct current component can be suppressed in the analog current signal.

[0037] The communication protocol can include Modbus, for example, Modbus / TCP. The data packet can be an Internet Protocol data packet, and the communication protocol can further include the Transmission Control Protocol / Internet Protocol (TCP / IP). Alternatively or additionally, the communication protocol can be Profibus. Alternatively or additionally, the communication protocol can be M-Bus or Foundation Fieldbus. Alternatively or additionally, the communication protocol can include Highway Addressable Remote Transducer (HART) or Controller Area Network (CAN).

[0038] Modbus may comprise a serial communication protocol used for transmitting information over serial lines between electronic devices. For example, the device using Modbus may be a sensor in an industrial automation system.

[0039] Profibus can comprise a digital communication protocol that can be used in automation technology. For example, the device using Profibus can be a sensor in a process automation system.

[0040] The Foundation Fieldbus (technically known as Foundation Fieldbus) can be a digital communication protocol for the use of a device in a process automation system. For example, the device can be a sensor in an oil or gas production or processing system.

[0041] HART can encompass a digital communication protocol used in process automation. For example, a HART-enabled device can be used to control a sensor in the chemical and petrochemical industries.

[0042] By means of a digital communication protocol according to CAN, the device can be a sensor in a charging station of an electric vehicle or a sensor in a vehicle, for example for autonomous driving.

[0043] The transducer can implement a protocol stack. The network interface can correspond to a physical layer of the protocol stack or a layer of the protocol stack below the communication protocol.

[0044] The network interface can be configured for asynchronous serial data transmission. The network interface can be configured according to the industry standard EIA-485 (also known as RS-485).

[0045] The network interface can comprise copper conductors or be designed for connecting copper conductors. The network interface can be designed according to 10BASE-T, for example for connecting unshielded twisted pair (UTP) cables of Category 3. The network interface can support transmission rates of 10 Mbps over a maximum distance of 100 meters. Alternatively or additionally, the network interface can be designed according to 100BASE-TX, for example for connecting UTP cables of Category 5 or higher. The network interface can enable a transmission speed of 100 Mbps over a maximum distance of 100 meters. Alternatively or additionally, the network interface can be designed according to 1000BASE-T (also known as Gigabit Ethernet), for example for connecting four twisted pairs of wires in a UTP cable of Category 5e or higher.The network interface can enable a transmission speed of 1 Gbit / s over a maximum distance of 100 meters. Alternatively or additionally, the network interface can be configured according to 10GBASE-T, for example, for connecting four twisted pairs of wires in a Category 6a or higher UTP cable. The network interface can enable a transmission speed of 10 Gbit / s over a maximum distance of 100 meters.

[0046] Alternatively or additionally, the network interface can comprise an optical fiber or be configured for connecting an optical fiber. The network interface can be configured according to 1000BASE-SX or 10GBASE-SR. The optical fibers can comprise fiber optic cables. Alternatively or additionally, the network interface can be an optical fiber connection.

[0047] If the network interface is an optical fiber (e.g., an optical fiber connection), it may not be possible to supply electrical power directly through this interface, as optical fibers are used to transmit light signals, not electrical energy. Alternatively or additionally, the power supply for the measuring transducer can be implemented using Power over Fiber (PoF). PoF can combine optical energy transmission with electrical energy supply by transmitting laser light via the optical fiber. The network interface can be designed (e.g., as part of the power supply) to convert laser light into electrical energy to power the measuring transducer. For example, the network interface can include a photovoltaic converter (in technical terms: photovoltaic power converters, PPC). This can efficiently convert the received laser light into electrical energy.

[0048] This arrangement allows the transducer to be used in environments where electrical power transmission via traditional means would be difficult or dangerous, such as in potentially explosive atmospheres or near high-voltage power lines, while still allowing data to be transmitted safely and without electromagnetic interference via the fiber optic cable. In either embodiment, the electrical power provided at the network interface (e.g., by the photovoltaic converter) may be routed through an electronic power supply circuit that converts or distributes the power into a form suitable for operating the transducer. This may include a voltage regulator and an energy storage device such as a capacitor or battery to smooth out fluctuations in the light signal and ensure a continuous supply.

[0049] The network interface can comprise a coaxial cable or be designed for connecting a coaxial cable. The network interface can be designed according to 10BASE2 (for example, with a BNC connector) or 10BASE5. The coaxial cable can have a characteristic impedance of 50 ohms.

[0050] The network interface may comprise a single twisted pair cable or be configured to connect a single twisted pair cable.

[0051] The network interface can be configured according to 100BASE-T1. The network interface can enable transmission of 100 Mbit / s over a single twisted-pair cable. The device can be used as a sensor in vehicles using 100BASE-T, e.g., for in-car entertainment systems or vehicle networks. Alternatively or additionally, the network interface can be configured according to 1000BASE-T1. The network interface can enable transmission of 1 Gbit / s over a single twisted-pair cable.

[0052] The network interface may include a connector or connector half according to the Ethernet, RJ-48, RJ-14, or IEC 63171 standards. The network interface may include a connector (or connector half) according to the base IEC 63171 standard, for example, IEC 63171-2 or IEC 63171-5. The RJ-48 standard is also known by the trade name RJ-45.

[0053] The data packet output at the network interface can include an identifier for the measuring transducer. Based on the identifier, the data packets of a plurality of different measuring transducers can be transmitted in a data network to which the network interface is connected for output (e.g., for data communication), and / or the data packets from a plurality of different measuring transducers can be recorded at a central receiving device with a unique assignment to the respective measuring transducer. The identifier can be unique in the data network, for example, a medium access control address (MAC address) of the network interface and / or an Internet protocol address of the measuring transducer. A variant of the first aspect relates to a measuring transducer for detecting electrical current through a current conductor. The measuring transducer comprises a current transformer that provides an analog current value from a measurement of an alternating current.The measuring converter further comprises a network interface for sending and receiving network signals. The measuring converter also comprises a microcontroller for controlling the network interface. The microcontroller is configured to provide a processed digital current signal based on the analog current value as network signals for transmission via the network interface. The measuring converter further comprises a power supply that is electrically powered by the network interface and / or the measured current.

[0054] The current transformer(s) can be subsequently placed and installed in a circuit without requiring the separation or interruption of the electrical conductor whose current is to be measured. The current is usually measured without contact. Accordingly, testing and, additionally or alternatively, certification of the circuit can be carried out before the current transformer is installed. Furthermore, currents from approximately 100 A to several thousand amperes (for example, up to and exceeding 10,000 A) can typically be measured without the need to insert components into the current-carrying elements. With many current transformer designs, only the conductor carrying the current to be measured needs to be enclosed by the device.

[0055] Well-known examples are small-signal converters or so-called measuring current transformers, which are available in closed ring designs or in folding designs.

[0056] In all aspects and variants, the digital current signals can be transmitted according to the selected transmission standard, for example, in Ethernet frames as an example of a data packet or other agreed standards. This can additionally include a recording time of the current value and, alternatively or additionally, data for identifying and optionally parameterizing the recording device during the transmission of the current values. They can also contain a reference to a trigger that caused the current value to be recorded.

[0057] The network interface for sending and receiving network signals can be designed for wireless data transmission or, alternatively or in addition to, wired data transmission. Wired transmission can be based on standards, for example, as a fieldbus. Common fieldbus variants are Interbus, Profibus, Profinet, Ethernet, EtherCAT, CAN bus, and HART. Some of these standards can include a power supply for the network interface. This can be the case, for example, with Ethernet (Power over Ethernet, PoE), where power of up to 90 watts is provided in various energy classes, which can be used to power the network interfaces and, if necessary, other components. Network interfaces can also handle the respective network protocol, encoding, and, if necessary, modulation of the data to be transmitted.Network interfaces can also integrate a standby mode, which can be entered after a specified period of inactivity for data transmission. Standby mode can be exited again based on a signal for pending data transmission in at least one transmission direction or upon other events.

[0058] Furthermore, wireless transmission standards can also be used for the network interface, either alternatively or in addition, whereby the power supply for the measuring transducer can also be wireless. The power supply can, for example, be designed as an inductive power supply without a connecting cable, which is now becoming widespread. Alternatively or additionally, the power supply can implement energy harvesting with or without wireless power supply. This involves harvesting small amounts of electrical energy from sources such as ambient temperature, vibrations, or air currents for the measuring transducer with low power. Alternatively or additionally, a cable can also be used for the power supply.

[0059] The microcontroller can be implemented as a microprocessor. It can include associated memory and input / output interfaces. It can include a standby mode to reduce its power consumption during such phases. The microcontroller can control the other components (also called modules) of the measuring transducer, in particular the network interface, the power supply, and, alternatively or additionally, the analog-to-digital converter.

[0060] The microcontroller can further be configured to provide a processed digital current signal based on the analog current value as network signals for transmission via the network interface. Optionally, the microcontroller can also enable phase-by-phase digitization, whereby analog transmission of the current value may also be possible between phases. Furthermore, the microcontroller can synchronize a measurement cycle with the phase position of the measured AC voltage and / or AC current, which are determined, for example, on a busbar. This enables the receiver to determine cos(phi) and active power. The power supply supplies the components of the measuring transducer. The power supply itself is fed by the network interface.The power supply or microcontroller can optionally parameterize the transmission power supply of the network interface, for example, with regard to the transmission power supply class to be set. The power supply, in turn, can supply the various components in a differentiated manner. This allows individual or group-specific differentiation of the individual powered components or groups of components with regard to the supply voltage, a standby mode, or current classes. A ground signal from the power supply can be used as a reference voltage when digitizing the tapped voltage. This allows for potential isolation between the power circuits, which are usually connected to the power grid, and the control electronics.

[0061] The measuring transducer can include permanent recording and storage of the analog current values. Alternatively, the derived digital current signals can be transmitted periodically or on request, and additionally or alternatively when the associated memory is full. Furthermore, transmission can be initiated in the event of deviating measured values ​​if the deviation exceeds a threshold. Optionally, the measuring transducer can include a voltage tap for power measurement.

[0062] Because the power supply is supplied by the current to be measured (e.g., by the current transformer or the voltage transformer) and / or by the network interface, a local or external power supply (e.g., a power supply) can be dispensed with, which can result in cost and space savings. In particular, the power supply can be customized to the measuring transducer's own power supply (supply) as well as the power supply of the measuring transducer components it supplies.

[0063] In exemplary embodiments, the current transformer can be designed as a small-signal transformer, a measuring current transformer, or an alternative design. The small-signal transformer or measuring current transformer is advantageously designed for retrofitting into the circuit, as it does not require modification. A Hall sensor as a current transformer can be used to measure direct currents. A plug-in current transformer offers a space-saving version of an uninterruptible measuring transducer (for detecting an electrical current flowing through a conductor). It can be designed as a fixed ring or as a foldable device for retrofitting into a circuit. Tubular rod current transformers are particularly suitable for compact designs. Wound-type current transformers are particularly well-suited for low primary rated currents.

[0064] In other embodiments, the measuring converter can comprise an analog-to-digital converter that is designed to receive the analog output signal of the current transformer. The analog-to-digital converter can be further designed to generate a digital current signal based on the analog current value. Furthermore, the voltage supply can be designed to electrically supply the analog-to-digital converter and alternatively or additionally the microcontroller, wherein the supply can be individually adjustable for the analog-to-digital converter and the microcontroller. Furthermore, the voltage supply can comprise a sleep mode at least for the analog-to-digital converter and alternatively or additionally for the microcontroller. Optionally, the length and alternatively or additionally also the time of the sleep modes for the analog-to-digital converter and for the microcontroller can differ from one another.Furthermore, the power supply can provide different voltages for the analog-to-digital converter and / or the microcontroller.

[0065] Advantageously, digitalization can be achieved with commercially available analog / digital components while at the same time providing greater freedom in the choice of types, for example with regard to the supply voltage of the power supply (supply) and its operation.

[0066] In exemplary embodiments, the current transformer, the analog-to-digital converter, the network interface, the microcontroller, and the power supply can be arranged in a single housing. Additionally or alternatively, the measuring converter can include a voltage transformer in the housing, the measured values ​​of which can be taken into account together with the measured values ​​of the current transformer when determining power.

[0067] The network protocol and the additional network protocol can be used for standardized data transmission, enabling efficient and robust communication between the measuring converter and a higher-level data network.

[0068] A second aspect relates to a system for processing electrical measured values. The system comprises a measuring converter according to the first aspect of the invention or its exemplary embodiments. The system further comprises a receiving device for receiving the processed digital current signal. The receiving device performs further processing of the processed digital current signal, which includes determining the currents determined using the current transformer. In each aspect, the measuring converter can be connected to a local network used for the measuring converter, for example, an Ethernet network. Alternatively, it can also be connected to the measuring converter via an additional transmission device (for example, for a further communication protocol), which can include a cellular mobile network or the like.Alternatively or additionally, the connection between the measuring converter and the receiving device can comprise a direct point-to-point connection (technically known as a PtP connection), a local network with distribution and routing elements, and additionally or alternatively, a combination with the internet. Thus, the measuring converter and the receiving device can use different transmission devices. The receiving device can be part of the data network or a PLCnext software or instance. For example, a Docker container with the analysis and evaluation software can run there.

[0069] The processing steps of the receiving device can include threshold values ​​for the measured current value, storage of the measured current value, evaluation of a historical development of the measured current value, and similar functions. It can also include feedback to the measuring converter, which can include, for example, parameterization of the current transformer or the measuring converter. This can further include a standby instruction to the measuring converter, the optionally parameterized trigger for another current measurement, a registration request or confirmation from the measuring converter, and the like. Accordingly, the receiving device is designed not only to receive the digital current signals but also to receive additional signals from the measuring converter. Furthermore, the receiving device can also transmit signals to and receive signals from other devices.For example, exceeding or falling below a threshold can trigger a message to a maintenance unit or control unit, for example, to indicate a fault. Furthermore, a functional change to the functions of the receiving device is possible, for example, to adapt to a modified measuring transducer, especially its current transformer.

[0070] Advantageously, part of the processing can be moved from the measuring converter to the receiving device and a more flexible function of the system can be achieved.

[0071] In exemplary embodiments, the receiving device can be designed to receive and process at least one further processed digital signal of the current from a further measuring transducer. The processing by the receiving device can comprise determining the further current determined using the further current transformer. By connecting the receiving device to a plurality of measuring transducers, the receiving device can act as a central device. Accordingly, the measurement data received from the various measuring transducers (i.e. the digital signals of the current and possibly voltage or power) can be related to one another. Depending on this, data packets can be sent to a controller (i.e. the microcontroller) of the measuring transducer (and additionally or alternatively to other devices outside the system) and / or their response can be received and evaluated.Thanks to digital decoupling, the arrangement of the receiving device in the data network can be chosen cost-effectively and flexibly.

[0072] For example, determining the current in the receiving device based on the digital current signal can involve scaling with respect to the different current transformers. For example, different types of through-hole transformers or Rogowski coils can generate different analog current measurements for the same current to be measured. By outputting the current, voltage, and / or power as a digital signal (e.g., as an absolute physical quantity), the receiving device can perform further processing of the digital signal in a type-agnostic manner.

[0073] Advantageously, the functional scope of the receiving device can be expanded and a cost-effective and flexible implementation can be achieved.

[0074] The receiving device and / or the measurement converter can comprise software for isolating applications using container virtualization. This can optionally be implemented as Docker software in a software container and, alternatively or additionally, for execution in a data network and, alternatively or additionally, for execution in a PLCnext environment.

[0075] In exemplary embodiments, the receiving device can be configured to register the measurement converter (and optionally the additional measurement converters). In this context or independently thereof, the measurement converter can be configured to receive a trigger signal (for example, from the central receiving device). Furthermore, the receiving device can be configured to parameterize the trigger signal.

[0076] The invention will be explained in more detail below with reference to the accompanying drawings based on preferred embodiments, which can be optionally combined with one another. They show:

[0077] Fig. 1 is a schematic representation of the measuring transducer for detecting an electric current flowing through a conductor,

[0078] Fig. 2 is a schematic representation of a housing of a current transformer in a first embodiment,

[0079] Fig. 3A is a schematic representation of a network interface in a first embodiment,

[0080] Fig. 3B is a schematic representation of a network interface in a second embodiment,

[0081] Fig. 4 is a schematic diagram of a system for processing digital current signals,

[0082] Fig. 5 is a schematic representation of a system for processing digital signals of the current in a first embodiment,

[0083] Fig. 6 is a schematic representation of a system for processing digital signals of the current in a second embodiment,

[0084] Fig. 6A is a schematic representation of a summation or difference formation in an embodiment of the receiving unit,

[0085] Fig. 7 is a schematic representation of an embodiment of the measuring converter with voltage tap, and

[0086] Fig. 8A and 8B are illustrations of a location of a network interface according to an embodiment of the measuring converter.

[0087] Herein, enumerations of the form A, B and / or C (and correspond with n>1 elements, which are not necessarily n=3) explicitly reveal the 2 n-1 cases A, B, C, A and B, A and C, B and C, and A and B and C. This means, in particular, that the mention of a conjunction (such as "and", "or", "and / or") between the penultimate and last element of the basic set refers, as is common in language, to all listed elements and not just to the last two elements. Fig. 1 shows a schematic block diagram of the measuring transducer 100 for detecting an electrical current flowing through a conductor. The measuring transducer 100 for detecting an electrical current flowing through a conductor comprises a current transformer 102 that provides an analog current measurement value of an alternating current measurement. The measuring transducer further comprises a network interface 106 for sending (and optionally receiving) data transmission signals and a microcontroller 108 for controlling the network interface 106.The arrows on the network interface 106 represent data exchange with one or more connected data networks or the like. The microcontroller 108 is configured to provide a processed digital current signal based on the analog current measurement value as a data transmission signal via the network interface 106 for outputting a data packet. Furthermore, the measurement converter 100 comprises a power supply 110, which is electrically powered by the network interface and / or by the current to be measured.

[0088] The current transformer 102 can be designed, for example, as a small-signal transformer, as a measuring current transformer or in a similar manner.

[0089] The measuring converter 100, for example the current transformer 102 (and / or the voltage transformer), can comprise the function of a sensor, i.e., a device that performs the function of a current or voltage transformer; deviates from the classic transformer principle; and / or contains electronic components for processing measured values, for example the AD converter 104.

[0090] In any embodiment disclosed herein, the current transformer 102 may include, for example, one of the following current sensors:

[0091] Low power converter

[0092] These converters are described in DIN EN 61869-6 as having an output power of < 1 VA. They are constructed like conventional converters and / or equipped with internal electronic circuitry and may also require auxiliary voltage, which is provided by the power supply 110. Output variables can be voltages or currents proportional to the primary current, but smaller than those of conventional converters, or even digital signals.

[0093] ROGOWSKI COIL

[0094] This converter comprises an ironless, wound ring or air and delivers a voltage proportional to the derivative d / _p / dt of the primary current / _p. Direct-imaging current sensor (direct-imaging converter)

[0095] These current sensors measure the current indirectly via the magnetic field generated by the current using one or more Hall probes. The Hall probe(s) are inserted into air slots in soft magnetic toroidal cores that enclose the current-carrying conductor.

[0096] Zero flux sensor or compensation current converter: In these converters, the secondary winding (compensation winding) serves to cancel the magnetic field generated by the primary current using an electronically generated compensation current. The magnetic flux in the core then becomes zero, with the compensation current being a nearly exact replica of the primary current. The measured value for generating the compensation current can be obtained, for example, using Hall sensors, magnetoresistive sensors, or an additional winding. It is then fed to the compensation winding as a compensation current via an electronic amplifier.

[0097] CURRENT TRANSFORMERS WITH DIGITAL OUTPUT (abbreviated DCT) These current transformers have a digital output, regulated in DIN EN 61869-9.

[0098] OPTOELECTRONIC CONVERTER (English: "optoelectronic converter")

[0099] These converters operate on the principle of the Faraday effect. This magneto-optical effect describes the rotation of the polarization plane of polarized electromagnetic waves (e.g., light) in a magnetic field. The angle of rotation is proportional to the field-causing current.

[0100] Most sensors require an additional auxiliary power source, which can be provided by the power supply 110.

[0101] In addition to a single-wire current transformer and a wound current transformer (each of which is an embodiment of the current transformer 102 and can optionally be combined with one of the six embodiments above), each of these embodiments can be modified according to one of the following applications.

[0102] Bar-primary converters and tube-type current transformers (also known as bar-primary converters or tube-type converters) are plug-in current transformers that are supplied with a primary bar section. Tube-type current transformers are a special type of plug-in current transformer in which a tubular copper insert (Cu sleeve) is located in the primary bar bushing. This design allows the transformer to be installed, for example, directly between the overlap of busbars or between busbars and disconnecting or fuse strips, etc. The term "bar-primary current transformer" is also used synonymously with plug-in current transformers, as these are usually pushed onto busbars. Transformers with a round primary conductor opening are also referred to as tube-type current transformers.

[0103] Site-winding current transformers (SWTs), or thread-winding converters for short, are wound current transformers that are supplied in the form of plug-in current transformers, with the user providing the primary winding themselves. When converting small currents, cost savings can be achieved by using plug-in current transformers for higher primary currents instead of the wound current transformers required here. The required higher primary current is achieved by winding (threading) the primary conductor several times through the primary busbar bushing. For example, by threading the primary conductor three times, a 150 A / 5 A plug-in current transformer can be converted into a current transformer with a transformation ratio (e.g., a division ratio) of 50 A / 5 A. Let's assume a transformation ratio of 25 A / 5 A is required, which could be achieved with a suitable wound current transformer. But let's also assume that a wound current transformer cannot be used.There can be various reasons for this; for example, the wound transformer may be too large, it may be too expensive, or the primary conductor cannot or may not be separated. In this example, a through-hole transformer with a ratio of 50 A / 5 A can be used. The primary conductor, which carries only 25 A, would have to be threaded twice through the primary conductor opening of the transformer.

[0104] The measuring converter (for detecting an electric current flowing through a current conductor) can comprise an analog-to-digital converter 104 configured to receive the analog output signal of the current transformer 102. The analog-to-digital converter 104 can be further configured to generate a digital current measurement value. The power supply 110 is then configured to electrically supply the analog-to-digital converter 104 and the microcontroller 108, i.e., to provide the supply voltage (supply) for the analog-to-digital converter 104 and the microcontroller 108.

[0105] The power supply 110 can include a sleep mode for the analog-to-digital converter 104 and, additionally or alternatively, for the microcontroller 108. Alternatively or additionally, the power supply 110 can provide different voltages for the analog-to-digital converter 104 and / or the microcontroller 108. Optionally, the length of the sleep modes for the analog-to-digital converter and / or the microcontroller can differ. Fig. 2 shows a schematic representation of a housing 150 of a current converter 102 in a first embodiment. The current converter 102, the analog-to-digital converter 104 (ADC), the network interface 106 (for example, an Ethernet interface), the microcontroller 108 (also symbolically abbreviated as "pC"), and the power supply 110 (technically: power supply) are arranged in a housing 150.

[0106] The measuring converter 102 can optionally comprise a voltage transformer 112 in the housing 150, the measured values ​​of which can optionally be taken into account together with the measured values ​​of the current transformer 102 in a power determination.

[0107] The housing 150 can have fastening elements for holding rails, which can be mounted, for example, in a control cabinet. Alternatively or additionally, the housing 150 can comprise signaling elements and, additionally or alternatively, setting elements with which the measuring transducer can signal, for example, operating or error states. The setting elements can be designed as switches, for example as a dual in-line package (DIP switch). The current transformer 102 can be in contact with the current conductor, for example the busbar, for example, by means of at least one spindle screw protruding from the housing 150.

[0108] This advantageously enables robust handling of the measuring converter 100, particularly during installation (or assembly), while simultaneously identifying (or configuring) operating parameters during use.

[0109] The network interface 106 comprises or enables a network connection. In exemplary embodiments, the network interface 106 can be configured as a local network connection or as a remote network connection. As a local network connection, it can be arranged, for example, with several components that further process the digital signals of the current on a circuit board or on circuit boards of a housing 150. The local network connection or the remote network connection can be configured as a wired network connection or as a wireless network connection, wherein a wireless power supply is also arranged with the wireless network connection. The remote network connection can be wired and include a power supply 110 of the measuring converter 100. It can correspond to one of the known fieldbuses that are further detailed above.

[0110] This advantageously allows the most suitable components to be used, increasing the effectiveness of the measuring converter. In other embodiments, the network connection can be implemented as Ethernet, Interbus, Profibus, Profinet, EtherCAT, CAN bus, HART, or a cellular network. Optionally, the microcontroller 108 can execute at least one communication protocol 160 of the network connection or another communication protocol 165 of the network connection.

[0111] In these or other embodiments, the measurement converter 100 can be configured to receive a trigger signal (preferably at the network interface 106) which initiates the acquisition of the analog current measurement value (and / or the output of the associated data packets). The triggered (e.g., event-driven) acquisition of the current measurement value can constitute an additional acquisition in a temporal acquisition pattern of the current measurement value. Alternatively, the triggered acquisition of the current measurement value can be a single acquisition of the current measurement value. Furthermore, the triggered acquisition of the current measurement value can constitute the start of an acquisition in a temporal acquisition pattern of the current measurement value. The trigger signal, in turn, can comprise an acquisition time for the analog current measurement value. Additionally or alternatively, an output format of the analog current measurement value can be included.Furthermore, or alternatively, a scaling instruction for recording the analog current measurement value and, additionally or alternatively, a coding instruction for the analog current measurement value may be included.

[0112] The trigger signal can be sent from a central receiving device that receives the current measurement values ​​(i.e., the data packets). The trigger signal can be transmitted to the measurement converter 100 as a signal coded according to the transmission standard used. The trigger signal can include an identification (i.e., an identifier), which is reused, for example, when outputting a data packet of the current measurement value acquired according to the trigger signal. Alternatively or additionally, the trigger signal can also be transmitted as a function of current measurements from other measurement converters. Furthermore, the trigger signal can specify a parameterization (e.g., of the current transformer 102) of the current measurement to be performed, which can be additional to or alternative to the above-mentioned parameter settings of the current transformer 102.

[0113] This advantageously allows for dynamic and flexible control of the current measurement value acquisition (through the central acquisition device).

[0114] Fig. 3A shows a schematic representation of a network interface 106 of the measurement converter 100 in a first embodiment. The network interface 106 is designed as a local network connection or as a remote network connection. The local network connection or the remote network connection is designed as a wired

[0115] Network connection 180 formed.

[0116] The wired network connection 180 can be configured as Ethernet, Interbus, Profibus, Profinet, Ethernet, EtherCAT, CAN bus, or HART. Optionally, the microcontroller 108 can execute at least one communication protocol 160 of the wired network connection 180 or another communication protocol 165 of the wired network connection 180.

[0117] In each embodiment, the measurement converter 100 can optionally receive the trigger signal (for example, as described above or according to reference numeral 170 in Fig. 6) for acquiring the analog current measurement value. For example, the trigger signal can include a capture time for the analog current measurement value and, additionally or alternatively, an output format (for example, the division ratio or a measurement range) of the analog current measurement value. Additionally or alternatively, a scaling instruction for acquiring the analog current measurement value and, furthermore, additionally or alternatively, an encoding instruction for the analog current measurement value can be included.

[0118] Fig. 3B shows a schematic representation of a network interface 106 of the measurement converter 100 according to a second embodiment. Fig. 3B differs from Fig. 3A in that the wired network connection 180 is replaced by the wireless network connection 190. This can be configured, for example, as a radio interface of a cellular mobile network (e.g., a 5G network) or a WLAN network (e.g., according to Wi-Fi or an IEEE 802.11 standard).

[0119] The power supply 110 can be designed as an inductive power supply without a cable connection and can be additionally or alternatively provided by energy harvesting, as explained in more detail in the first aspect, see above. The remaining features can be identical to the embodiment of Fig. 3A.

[0120] In a first variant of each embodiment, the power supply 110 can comprise an inductive current transformer 102 as an energy harvester. The current transformer 102 is designed as an inductive measuring transformer, which essentially consists of a primary winding—in this case, the current conductor 300 itself—and a secondary winding. The current flowing through the current conductor 300 induces a magnetic field, which is alternating current, provided the mains current is alternating current. The secondary winding of the current transformer captures this magnetic field and thus the voltage induced thereby, from which, in addition to the analog current signal, the power supply 110 is also fed. In a second variant of each embodiment, the power supply 110 can comprise a rectifier and a voltage regulator. The voltage tapped from the secondary winding of the current transformer 102 is passed through a rectifier circuit to be converted into a direct current.The voltage can then be brought to a suitable level for powering the electronics of the measuring converter 100 using a voltage regulator or DC-DC converter.

[0121] In a third variant of each embodiment, the power supply 110 can include electrical energy storage elements. To compensate for short-term fluctuations in the current flow or power outages, capacitors or small accumulators can be integrated downstream of the voltage regulator. These storage elements ensure a constant power supply, even if the current to be measured is temporarily lost or too weak to directly supply the components of the measuring converter 100.

[0122] In a fourth variant of each embodiment, the measurement converter 100 can perform power management. For example, the microcontroller 108 (or a dedicated power management chip) can be configured to optimize the generation, storage, and consumption of energy (e.g., time-dependent). This chip or function would ensure that the microcontroller 108 and the network interface 106 are sufficiently supplied with power at all times, while simultaneously optimally utilizing the energy in the storage element.

[0123] In some embodiments of the measuring transducer 100, the power supply 110 allows it to operate autonomously and does not require an external power supply. Since the current transformer 102 is used both for measurement and for providing electrical energy (i.e., supply), this is an efficient solution for using the measuring transducer 100 in electrical distribution networks.

[0124] Fig. 4 shows a schematic representation of a system 200 for processing digital stream signals. This includes the measurement converter 100 according to the first aspect and optionally one or more embodiments thereof. The system 200 further comprises a receiving device 302 for receiving the processed digital stream signal (i.e., the data packets), optionally wherein further processing of the processed digital stream signal is performed in the receiving device 302.

[0125] Further processing includes determining the currents detected by current transformer 102. For example, currents (or voltages) in additional side branches can be determined by summing or subtracting (according to Kirchhoff's rules), as shown schematically in Fig. 6A. Alternatively or additionally, the received current (or voltage) values ​​can be checked for consistency by summing or subtracting. This allows leakage currents and voltage drops to be detected to prevent accidents. Alternatively or additionally, the deviation can be an input value for predictive maintenance.

[0126] The signaling between the measuring converter 100 and the receiving device 302 can be carried out via one or more entities, for example via the Internet as data network 300 and additionally or alternatively via other connecting devices, as explained in more detail above with regard to the second aspect of the invention.

[0127] Fig. 5 shows a schematic representation of a system 200 for processing digital current signals in a first embodiment. Shown is the receiving device 302, which is configured to receive and process a processed digital current signal from the measuring transducer 100 and at least one further processed digital current signal from another measuring transducer 100'. The processing includes determining the current determined by the current transformer 102 and determining the further current determined by another current transformer 102.

[0128] Optionally, the receiving device 302 comprises software 310 for isolating applications using container virtualization, which can optionally be implemented as Docker software in a software container. Alternatively or additionally, the software can be executed in a data network 330 and / or arranged for execution in a PLCnext environment 340. Signaling between the measurement converter and the receiving device 302 can be conducted via one or more entities, for example, via the internet, a direct point-to-point connection, or the like.

[0129] Container virtualization involves combining application code with the operating system libraries and dependencies required to run the code into a single executable file, referred to as a container, that can be executed consistently in any infrastructure. Accordingly, the implementation of the measurement converter 100 as a container and / or the implementation of the receiving device 302 can be deployed in various environments with little or no further adaptation. This infrastructure can include, for example, data networks 330, servers, computers in local networks, or similar devices.

[0130] Docker software is a free software for isolating applications using container virtualization. Docker simplifies application deployment because containers containing all necessary packages can be easily transported and installed as files. Alternatively or in addition, the infrastructure can include PLCnext, a system for industrial automation with open hardware, modular engineering software, a global community, and a digital software marketplace. It is supported by Phoenix Contact.

[0131] Advantageously, this can accelerate the creation of the measuring converter 100 and / or the receiving device 302 and facilitate their adaptation to different systems, such as the PLCnext environment 340.

[0132] Fig. 6 shows a schematic representation of a system 200 for processing digital current signals in a second embodiment. This system includes the receiving device 302, which is configured to register 320 the first measuring transducer and the further measuring transducer 100'. Furthermore, the receiving device 302 is configured to transmit a trigger signal 170 to the registered measuring transducer 100 or the further registered measuring transducer 100'. Optionally, the receiving device 302 can be configured to parameterize the trigger signal 170 (not shown).

[0133] Additionally, the data transmission signal received by the measuring converter 100 and the further measuring converter 100' at the receiving device 302 can be based on the trigger signal 170 (not shown). Further additionally, the further measuring converter 100' can comprise a plurality of further measuring converters 100' (not shown). Thus, the digital current signals of the measuring converter and the digital current signals of the further measuring converters 100' can be correlated with one another (not shown). Optionally, the digital voltage measurement values ​​of the measuring converter and the digital voltage measurement values ​​of the further measuring converters 100' can also be correlated with one another.

[0134] Further optionally, the receiving device 302 can include an anomaly detector 350 for the processed digital signal of the current. The anomaly detector 350 can be configured for each measuring converter and, in addition or alternatively, for the combined view of the measuring converter and the other measuring converters.

[0135] Finally, anomaly detection 350 can be based on artificial intelligence algorithms.

[0136] In one embodiment, the evaluation electronics with a (preferably high-resolution) analog-to-digital converter 104 (ADC) is installed directly in the housing of the current transformer 102. The value digitized by the ADC 104 is processed by a microcontroller 108 and made available, for example, on an Ethernet interface (e.g., the network interface 106) for Ethernet-capable protocols. The power supply (e.g., as a local power supply) is also implemented via the Ethernet interface using a power supply from the Ethernet (technically known as Power over Ethernet protocol, PoE), with the PoE supply feeding an internal power supply 110.

[0137] In each embodiment, the electronics (network interface 106, microcontroller 108, power supply 110, analog-to-digital converter 104) are preferably shielded against EMC influences (electromagnetic compatibility, EMC) in a manner adapted to the environment.

[0138] Embodiments of the inventive measuring converter 100 and the inventive system 200 include a power save mode in which parts of the measuring converter 100 or the entire measuring converter 100 can be temporarily placed in a standby mode. The standby mode can be terminated by a wake-up signal from a timer expiration.

[0139] Furthermore, it is possible to negotiate an Ethernet energy class (or power class or PoE class) from several energy classes to supply the measuring converter 100.

[0140] Advantageously, embodiments of the invention result in a significantly reduced cabling effort together with savings in separate devices (evaluation units, for example "EMpro"), a reduction in the CC>2 emissions during manufacture and operation of the measuring converter 100 and system 200, a reduction in the probability of failure (technically known as Mean Time To Failure, MTTF) as well as the connectivity with higher-level systems, for example control or maintenance computers.

[0141] Furthermore, there is the possibility of predictive maintenance. This is a prediction that can, in particular, predict errors or failures. This can be done based on summation functions or statistics (e.g., training and deriving a neural network system) based on feedback (e.g., data packets) from the entire system 200, including its plurality of measuring transducers 100, 100'.

[0142] In some embodiments, the predictive maintenance results can also lead to the parameterization of the measuring transducers and, in addition or alternatively, the system. For example, in the case of temperature deviations of individual measuring transducers compared to the average of the measuring transducers 100, 100', the standby time of the affected measuring transducers can be extended. Alternatively, or in combination with the standby times, the periods between trigger signals can be increased. For comparable systems 200, a preset for their operating ranges can also be achieved based on the predictive maintenance results (technical term: teach-in mode).

[0143] In each embodiment, the current transformers 102 can be used as sensors for alternating current. The current transformer 102 can have a voltage output as an analog current signal and is connected via the AD converter 104 to the microcontroller 108 as an energy meter or current measuring device. The input variable, i.e. the current to be measured, is the alternating current in the current conductor 300 enclosed by the current transformer. This can be between 0 A and several thousand A or more. The output variable is an output current corresponding to the input current. For example, 5 A as an output current can correspond to an input current of 800 A. This analog current value is sampled and digitized by the AD converter 104. The microcontroller, as the evaluation unit, knows which division ratio is set or applies.

[0144] Because the measurement converter 100 provides the data from the current transformer 102 directly as digital values, the receiving unit 302 no longer requires knowledge of the division ratio, which traditionally limited the application. The current transformer 102 or its AD converter 104 can, for example, provide a 64-bit value. Furthermore, the limitation on the number of measurement channels on the conventional analog evaluation unit is eliminated, since the digital values ​​can be retrieved from many measuring points via the communication protocol 160, 165. Furthermore, the physical presence of an evaluation unit is eliminated.

[0145] The optional voltage information based on the analog voltage signal 114 from the voltage tap 112 shown schematically and by way of example in Fig. 7 (for example, as part of a mechanical assembly aid 116 on the housing 150) provides all the parameters for calculating power and / or energy. The evaluation of the digital measured values ​​can also be performed digitally. This means that the receiving device 302 can be implemented by a cloud service or a PLCnext application (PLCnext app for short).

[0146] An independent device aspect, which can be supplemented with any feature of the measuring transducer 100 mentioned herein, can be described as follows. For this solution, the evaluation electronics with a high-resolution ADC 104 are installed directly in the housing 150 of the current transformer 102. The value digitized by the ADC 104 (e.g., the current) is processed by a microcontroller unit 108 (technically known as an MCU) and made available on the Ethernet interface 106 for Ethernet-capable protocols 160, 165. The power supply is also achieved via the Ethernet interface 106 using the "Power over Ethernet" (PoE) protocol. The electronics are preferably shielded against EMC influences, adapted to the environment.

[0147] Fig. 8A and 8B show, in perspective and in a top view, a position of a built-in socket of the network interface 106 as an Ethernet connection 180.

[0148] Together with the optional at least one voltage tap 112, all physical quantities necessary for calculating power and energy can be recorded.

[0149] Although the invention has been described with reference to exemplary embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted. Furthermore, many modifications may be made to adapt a particular installation situation or circuit arrangement to the teachings of the invention. Consequently, the invention is not limited to the disclosed embodiments, but encompasses all embodiments falling within the scope of the appended claims.

[0150] Reference symbol

[0151] 100 measuring transducers (for detecting an electric current flowing through a conductor)

[0152] 100', 100", 100"' Other measuring converters

[0153] 102 current transformers (e.g. small signal transformers, measuring current transformers, etc.)

[0154] 104 Analog-to-digital converters (also: AD converters or ADCs)

[0155] 106 Network interface

[0156] 108 microcontrollers

[0157] 110 Power supply

[0158] 112 voltage converters

[0159] 114 Analog voltage signal

[0160] 116 Assembly aid

[0161] 150 housings

[0162] 160 Communication protocol

[0163] 165 Additional communication protocol

[0164] 170 trigger signal

[0165] 180 Wired network connection

[0166] 190 Wireless network connection

[0167] 200 systems

[0168] 300 power conductors (e.g. busbar)

[0169] 302 Central receiving device

[0170] 310 Software

[0171] 320 Registration

[0172] 330 Data network, for example a "cloud"

[0173] 340 PLCnext environment

[0174] 350 Anomaly Detection

Claims

Patent claims 1 . A measuring transducer (100) for detecting an electrical current flowing through a current conductor (300), comprising: a current transformer (102) configured to generate an analog current signal corresponding to the electrical current flowing through the current conductor (300); an analog-to-digital converter (104) configured to generate a digital current signal corresponding to the analog current signal; a network interface (106); a microcontroller (108) configured to output a data packet according to a communication protocol (160; 165) at the network interface (106) based on the digital current signal; and a power supply (110) of the measuring transducer (100), which is fed by the network interface (106) and / or the current to be detected.

2. The measuring converter (100) according to claim 1, further comprising: a voltage converter configured to generate an analog voltage signal corresponding to an electrical voltage applied to the current conductor (300); a further analog-to-digital converter (104) configured to do so, and / or the analog-to-digital converter (104) further configured to generate a digital voltage signal corresponding to the analog voltage signal, wherein the microcontroller (108) is configured to output the data packet according to the communication protocol (160; 165) at the network interface (106) on the basis of the digital current signal and the digital voltage signal.

3. The measuring transducer (100) of claim 2, wherein the microcontroller (108) is configured to determine a power based on the digital signal of the current and the digital signal of the voltage, wherein the output data packet indicates the determined power.

4. The measuring converter (100) according to any one of claims 1 to 3, wherein a bit depth and / or a dynamic range of the digital signal is independent of the analog signal; and / or wherein the analog-to-digital converter (104) or the further analog-to-digital converter (104) is configured to generate the digital signal of the current by sampling the analog signal of the current, optionally with a bit depth of at least 64 bits, and / or to generate the digital signal of the voltage by sampling the analog signal of the voltage, optionally with a bit depth of at least 64 bits; and / or wherein the data packet contains the current flowing through the current conductor (300) Current, the voltage applied to the current conductor (300) and / or the specific power, optionally in an absolute physical unit and / or independently of a division ratio of the current transformer (102) and / or the voltage transformer.

5. Measuring converter (100) according to one of claims 1 to 4, wherein the analog-to-digital converter (104) or the further analog-to-digital converter (104) is arranged in a housing (150) of the current transformer (102), and / or wherein the measuring converter (100) comprises a housing (150) in which the current transformer (102) and at least one of the following features is arranged: the analog-to-digital converter (104); the further analog-to-digital converter (104); the network interface (106); and the microcontroller (108).

6. The measuring converter (100) according to one of claims 1 to 5, wherein the power supply (110) is designed to electrically supply at least one of the following components: the analog-to-digital converter (104); the further analog-to-digital converter (104); the network interface (106); and the microcontroller (108); and / or wherein the network interface (106) is connected or connectable to at least two data lines and the power supply (110) is designed to feed at least one of the aforementioned components with a supply voltage superimposed on the data lines.

7. Measuring converter (100) according to one of claims 1 to 6, wherein the current transformer (102) comprises: - a small signal converter; - a measuring current transformer; - a Rogowski coil; - a direct-imaging current sensor, optionally a Hall sensor; - a zero-flux transformer, optionally with a compensation winding, through which a current signal flows as the analogue signal of the current to be measured and is electronically controlled to compensate for a magnetic field generated by the current; and / or - optoelectronic converter.

8. Measuring converter (100) according to one of claims 1 to 7, wherein the Communication protocol (160; 165) comprises at least one of the following protocols: - Modbus, optionally Modbus / TCP, wherein the data packet is an Internet Protocol data packet and the communication protocol (160; 165) further comprises the Transmission Control Protocol / Internet Protocol, TCP / IP (165); - Profibus; - M-Bus; - Foundation fieldbus; - Highway Addressable Remote Transducer, HART; and - Controller Area Network, CAN.

9. The measuring converter (100) according to any one of claims 1 to 8, wherein the network interface (106) is configured for asynchronous serial data transmission.

10. The measuring converter (100) according to any one of claims 1 to 9, wherein the network interface (106) comprises copper conductors or is configured to connect copper conductors.

11. The measuring converter (100) according to any one of claims 1 to 10, wherein the network interface (106) comprises an optical fiber or is configured to connect an optical fiber.

12. The measuring converter (100) according to any one of claims 1 to 11, wherein the network interface (106) comprises a coaxial cable or is configured to connect a coaxial cable.

13. The measuring converter (100) according to any one of claims 1 to 12, wherein the network interface (106) comprises a single twisted pair cable or is configured to connect a single twisted pair cable.

14. The measuring converter (100) according to any one of claims 1 to 13, wherein the network interface (106) comprises a connector or a connector half according to the Ethernet, RJ-48, RJ-14 or IEC 63171 standard.

15. The measuring converter (100) according to any one of claims 1 to 14, wherein the data packet output at the network interface (106) comprises an identifier of the measuring converter (100).

16. A system (200) for detecting an electric current flowing through a current conductor (300), comprising: - at least one current conductor (300); - at least two measuring transducers (100) according to one of claims 1 to 15, which are arranged on the at least one current conductor (300) for detecting the current flowing therein; and - a receiving device (302) connected via a data network (330) to the network interfaces (106) of the at least two measuring converters (100) for exchanging data packets.

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