Digital input module for measuring power in a stationary energy grid

Abstract

A digital input module for measuring electrical power in a stationary energy grid comprising electrical loads having a plurality of interfaces for respective current measuring modules which are connectable to a respective electrical load and configured to measure a current supplied to a connected electrical load, at least one interface for a voltage measuring module which is connectable to a respective electrical load and configured to measure a voltage supplied to a connected electrical load, a central computation unit configured to receive measurement data from current measuring modules and a voltage measuring module and to synchronize measurements of the current measuring modules and the voltage measuring module in order to ascertain electrical parameters of the energy grid and / or the electrical loads.

Description

[0001] Digital input module for power measurement in a stationary energy network

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a digital input module for electrical power measurement in a stationary energy network with electrical consumers.

[0004] TECHNICAL BACKGROUND

[0005] To assess network conditions in an energy network, it is often necessary to measure currents, voltages, frequencies and power, as well as to analyze the measured values.

[0006] For example, in local network substations, there are usually several low-voltage outgoing lines where measurements are required. A (comprehensive) voltage measurement is often sufficient, whereas a separate current measurement may be required at each voltage outgoing line.

[0007] EP3807657A1 shows a sensor device for a terminal block arrangement.

[0008] The sensor device includes sensors to measure relevant physical quantities, such as current and voltage.

[0009] SUMMARY OF THE INVENTION

[0010] Accordingly, it is provided:

[0011] A digital input module for measuring electrical power in a stationary energy network with electrical consumers, comprising a plurality of interfaces for each current measuring module, which can be connected to a respective electrical consumer and are configured to measure the current supplied to a connected electrical consumer, at least one interface for a voltage measuring module, which can be connected to a respective electrical consumer and is configured to measure the voltage supplied to a connected electrical consumer, a central processing unit which is configured to receive measurement data from current measuring modules and a voltage measuring module and to synchronize measurements of the current measuring modules and the voltage measuring module in order to determine electrical parameters of the energy network and / or the electrical consumers.

[0012] An energy network is, for example, a local network or an industrial energy network.

[0013] A local grid is a part of the electrical power system that operates at the local level. It forms the connection between the higher-level high-voltage grid and end users by transforming electrical energy to a level suitable for use in homes, businesses, and other facilities. Nodes in local grids are called local grid stations.

[0014] Industrial energy grids are supply systems designed to ensure energy efficiency, security of supply, and flexibility in industrial environments. These grids enable the provision and distribution of electrical energy and other forms of energy in industrial facilities.

[0015] An electrical consumer is, for example, a house connection of a local network, a voltage tap, a peripheral device of an industrial energy network or the like.

[0016] In an energy grid, the term "voltage outlets" refers to the points or locations in the grid where electrical energy is taken off in the form of electrical voltage. These points can be consumers, buildings, industrial plants, machines, or other facilities that require electrical energy for their operation.

[0017] Voltage outgoing lines are part of the low-voltage network, which represents the last section of the power supply before the electrical energy reaches the end users.

[0018] A stationary energy grid is not moving. Vehicle energy grids are non-stationary or moving energy grids.

[0019] The basic idea of ​​the invention is to separate a sensor system for power measurement from sensors for current measurement and voltage measurement of a digital input module. Accordingly, the invention proposes to create measuring modules that are configured to measure either current or voltage. Thus, a digital input module can be constructed from measuring modules for current measurement or voltage measurement, depending on the application.

[0020] Accordingly, a digital input module is provided with at least one interface for a voltage measuring module and with a plurality of interfaces for each current measuring module.

[0021] In this patent application, measurement modules are configured to measure either current or voltage. Accordingly, voltage measurement modules are not suitable for measuring current, and current measurement modules are not suitable for measuring voltage.

[0022] This reduces the size of a digital input module compared to a digital input module with combined measuring modules for voltage and current measurement, assuming that the voltage in a power grid is approximately identical for several electrical consumers and accordingly fewer voltage measuring modules than current measuring modules are required in a digital input module.

[0023] A central processing unit, which is configured to receive measurement data from the current measuring modules and the voltage measuring module and to synchronize measurements from the measuring modules, enables the power measurement in a three-phase system to be divided into measuring modules for either current measurement or voltage measurement.

[0024] Consequently, for additional electrical consumers whose electrical power is to be determined, only one interface for current measurement needs to be added in the digital input module.

[0025] Furthermore, variants for current and voltage measurements can be individually combined for a specific application. In the following, one or more current measuring modules and one voltage measuring module are also referred to as measuring modules.

[0026] Advantageous embodiments and further developments emerge from the further subclaims and from the description with reference to the figures of the drawing.

[0027] According to a preferred development of the invention, the central processing unit is configured to control current measuring modules and a voltage measuring module based on delay times of the measuring modules for measuring and / or delay times of the measuring modules for processing measurement data.

[0028] The lag time of a measurement refers to the time elapsed between the time an event actually occurs and the time it is detected or displayed by the measuring device. This delay can be caused by various factors and impacts the accuracy and reliability of measurements.

[0029] Accordingly, it is conceivable to determine the delay times of measurement modules in advance to synchronize measurements and store them on the central processing unit. This includes both the delay time for a measurement and a delay time corresponding to the time required for processing the measurement data and transmitting it to the central processing unit. Based on these delay times, the central processing unit can specify a minimum cycle time such that all measurement data is transmitted synchronously in one cycle and assigned an identical time stamp.

[0030] According to a preferred development of the invention, the digital input module is designed as a module carrier, wherein the module carrier comprises the central processing unit or is connected to a central processing unit, and interfaces for the measuring modules are designed as plug connectors.

[0031] This allows for a minimal modular base frame that can be assembled from measurement modules for current or voltage measurement, depending on the application. The interfaces, designed as connectors, ensure quick and user-friendly configuration of a digital input module, allowing the application-specific measurement modules to be easily inserted into or removed from the module carrier.

[0032] According to a preferred development of the invention, a digital input module comprises a plurality of current measuring modules comprising an interface for connection to an electrical consumer and to at least one voltage measuring module.

[0033] According to a preferred development of the invention, the measuring modules each comprise a microprocessor to measure phase-specific variables related to a connected electrical consumer or a power grid.

[0034] Thus, measurement data from a measuring module can be preprocessed using the microprocessor by determining phase-specific variables, such as frequency, RMS values, phase angles, phase current angles, and / or the like, to reduce the load on the central processing unit. Furthermore, the microprocessor enables the transmission of measurement data to the central processing unit in a predetermined format adapted to data processing by the central processing unit.

[0035] The central processing unit can be configured, for example, as a CPU. The central processing unit can be configured to determine apparent power, active power, reactive power, power factor, total power factor, voltage quality, and / or the like. The combined analysis of these electrical parameters enables a comprehensive assessment of the grid quality and power balance in a three-phase system.

[0036] Furthermore, it is conceivable that one or more measuring modules have analog-to-digital converters to enable synchronous sampling of three phases in a three-phase current cycle at a synchronization time in a data bus cycle.

[0037] A data bus is a part of a computer or electronic system responsible for transferring data between different components or modules. The data bus enables communication and data exchange between different parts of a computer or electronic device.

[0038] A data bus cycle refers to the period of time during which a data bus transfers information between different components of a computer or electronic system. This cycle encompasses the transfer of data over the data bus and can include various phases or clock cycles.

[0039] A complete three-phase current cycle comprises a complete rotation (360 degrees) of the sine waves of all three phases. The duration of a three-phase current cycle depends on the frequency of the three-phase current and is measured in Hertz (Hz).

[0040] It is understood that a measuring module for connection to a digital input module as described above, with an interface to an electrical consumer of a stationary energy network, an interface to the digital input module, which is configured to measure either a voltage supplied to an electrical consumer or a current supplied to an electrical consumer, is encompassed by the invention.

[0041] Accordingly, a measuring module with a microprocessor is also advantageous for measuring phase-specific variables related to a connected electrical consumer or energy network.

[0042] According to a preferred embodiment of the invention, a current measuring module comprises four current inputs, in particular I1, I2, I3, and one input IN. Alternatively, current measuring modules with three current inputs I1, I2, I3 or I1, I2, IN are also conceivable. A neutral conductor may be omitted or irrelevant.

[0043] A voltage measuring module can have four voltage inputs U1, U2, U3, UN,

[0044] In a three-phase system, the designations I1, I2, and I3 represent the three phases of the three-phase current, while I1 represents the neutral conductor. I1, I2, and I3 represent the three phases of a three-phase system. The neutral conductor is connected to the midpoint of the voltage and is often used as a reference point for the phases. It also serves as a return conductor for the unbalanced currents in the system.

[0045] It is advantageous if the measurement module interfaces of a digital input module are suitable for connecting both a current measurement module and a voltage measurement module. This ensures a high degree of modularity of a digital input module, as a digital input module can be connected to any configuration of current measurement modules and voltage measurement modules, provided the number of measurement modules does not exceed the number of slots of a digital input module.

[0046] It is also advantageous if a digital input module has an interface for connecting to another digital input module. This ensures expandability with more slots for additional measurement modules. The interface can also be suitable for connecting to a control unit.

[0047] TABLE OF CONTENTS OF THE DRAWINGS

[0048] The present invention will be explained in more detail below with reference to the exemplary embodiments shown in the schematic figures of the drawings. In the drawings:

[0049] Figure 1 is a schematic diagram of an embodiment of the invention;

[0050] Figure 2 is a schematic block diagram of an embodiment of the invention.

[0051] The accompanying drawings are intended to provide a further understanding of embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the noted advantages will be apparent upon review of the drawings. Elements of the drawings are not necessarily shown to scale relative to one another.

[0052] In the figures of the drawings, identical, functionally identical and acting elements, features and components are provided with the same reference symbols, unless otherwise stated.

[0053] DESCRIPTION OF EMBODIMENTS

[0054] Figure 1 shows a schematic diagram of a digital input module 100 and a current measuring module 1, which is shown in a plug-in direction to the digital input module 100.

[0055] The digital input module 100 comprises six interfaces 7, into each of which a measuring module, i.e., a current measuring module or a voltage measuring module, can be plugged. The interfaces 7 each form a slot for a measuring module. The digital input module 100 comprises a data interface 14 for a data bus on a rear panel in a central area, which connects the digital input module 100, for example, to a control unit.

[0056] Figure 2 shows a schematic block diagram of a circuit of a digital input module 100, which in Figure 2 is connected to measuring modules, namely a current measuring module 1, a current measuring module 2 and a voltage measuring module 3.

[0057] Dots between the current measuring module 2 and the voltage measuring module 3 indicate that the digital input module 100 has further interfaces (not shown) for connection to further measuring modules (not shown).

[0058] Accordingly, the digital input module 100 comprises an interface 7, which connects the current measuring module 1 to a central processing unit 10 of the digital input module 100 via a data bus. Furthermore, the digital input module 100 comprises an interface 8, which connects the current measuring module 2 to a central processing unit 10 of the digital input module 100 via a data bus. Furthermore, the digital input module 100 comprises an interface 9, which connects the voltage measuring module 3 to a central processing unit 10 of the digital input module 100 via a data bus.

[0059] The current measuring module 1 comprises three current inputs, which are collectively assigned the reference numeral 11, and a microprocessor 4. Each current input comprises a + / - input. The current measuring module 2 comprises three current inputs, which are collectively assigned the reference numeral 12, and a microprocessor 5. Each current input comprises a + / - input. The voltage measuring module 3 comprises three voltage inputs, which are collectively assigned the reference numeral 13, and a microprocessor 6. Each voltage input comprises an input for U1, U2, or U3, as well as for a neutral conductor.

[0060] The microprocessors 4, 5, 6 form the respective interfaces 7, 8, 9 to connect the respective measuring module with the central processing unit 10.

[0061] The central processing unit 10 is designed as a CPU and includes an interface 14 for connection to a control unit via a data bus.

[0062] Reference symbol

[0063] 1 current measuring module

[0064] 2 current measuring module

[0065] 3 Voltage measuring module

[0066] 4 microprocessor

[0067] 5 microprocessor

[0068] 6 microprocessor

[0069] 7 Interface

[0070] 8 Interface

[0071] 9 Interface

[0072] 10 central processing unit

[0073] 11 power inputs

[0074] 12 power inputs

[0075] 13 voltage inputs

[0076] 14 Interface

[0077] 100 digital input modules

Claims

Patent claims 1. Digital input module for electrical power measurement in a stationary energy network with electrical consumers with - a plurality of interfaces for each current measuring module, each of which can be connected to an electrical consumer and is configured to measure the current supplied to a connected electrical consumer, - at least one interface for a voltage measuring module, which can be connected to a respective electrical consumer and is configured to measure a voltage supplied to a connected electrical consumer, - a central processing unit configured to receive measurement data from current measuring modules and a voltage measuring module and to synchronise measurements from the current measuring modules and the voltage measuring module in order to determine electrical parameters of the energy network and / or the electrical consumers.

2. Digital input module according to claim 1, wherein the central processing unit is configured to control current measuring modules and a voltage measuring module, hereinafter referred to as measuring modules, based on delay times of the measuring modules for measuring and / or delay times of the measuring modules for processing measurement data.

3. Digital input module according to one of the preceding claims, wherein the digital input module is designed as a module carrier which comprises the central processing unit or is connected to the central processing unit, and the interfaces for the measuring modules are designed as plug connectors.

4. Digital input module according to one of the preceding claims, with a plurality of current measuring modules comprising an interface for connection to an electrical consumer in each case and with at least one voltage measuring module with an interface for connection to a electrical consumers.

5. Digital input module according to claim 4, wherein the measuring modules are connected to the central processing unit via a data bus.

6. Digital input module according to one of the preceding claims 4 or 5, wherein the measuring modules each have a microprocessor to determine phase-specific quantities, each of which is related to a connected electrical consumer or the power grid.

7. Measuring module for connection to a digital input module according to one of the preceding claims, with an interface to an electrical consumer of a stationary energy network and an interface to the digital input module, which is configured to measure either a voltage supplied to an electrical consumer or a current supplied to an electrical consumer.

8. Measuring module according to claim 7, comprising a microprocessor to determine phase-specific quantities, each of which is related to a connected electrical load or the power grid.

9. Measuring module according to claim 7 or 8, which is designed as a current measuring module and has four current inputs, in particular I1, I2, I3 and an input for IN.

10. Energy network with several voltage outputs, which supply one or more electrical consumers with electrical energy, a control unit and with a digital input module according to one of the preceding claims 4 - 6, if dependent on claim 4, wherein the digital input module is connected to the control unit, and the control unit is set up to control energy transmitted in the energy network and / or electrical consumers in the energy network on the basis of data transmitted from the digital input module to the control unit, to control.

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