Switching device

Abstract

The invention relates to a switching device (100). According to the invention, the switching device (100) has two or more current paths (13, 23, 33) by means of which an energy feed for a downstream load (53) can be achieved. An electronic interruption unit (11) and a mechanical switch (12) are arranged in each case in series in the current paths (13, 23, 33). The current paths (13, 23, 33) are each associated with a decentralized control unit (111, 211, 311) which is designed to drive the electronic interruption unit (11, 21, 31).

Description

Technical Field

[0001] The invention relates to a switching device having two or more current paths, via which energy can be fed to downstream electrical loads, wherein an electronic interruption unit and a mechanical switch are respectively arranged in series in the current paths. The invention also relates to a method for operating the switching device. Background Art

[0002] Switching devices for switching the energy supply of downstream electrical loads are known. For example, motor starters are used directly on the grid to control and protect three-phase motors. A distinction is made here between direct-on-line starters and soft starters. Direct-on-line starters switch the grid voltage directly to the motor, while soft starters have the possibility of limiting or slowly increasing the effective voltage on the motor during the starting time by phase gating, see the two diagrams on page 21C-6 in Siemens AG, Grundlagender Niederspannungs-Schalttechnik, 2008 (http: / / www.siemens.de / lowvoltage / grundlagen).

[0003] Current motor starters are usually implemented by corresponding wiring of contactors, see DE 10 2008 026 376 A1 (Siemens AG, December 2, 2009), or are implemented as hybrid starters, see DE 10 2012 214 814 A1 (Siemens AG, February 27, 2014), where "hybrid" refers to the combination of robust relay technology and wear-free semiconductor technology. In both embodiments, a central control unit drives the switching element of the motor starter to either assume a current-conducting state or a current-blocking state. For this purpose, the central control unit receives measured values ​​for current, voltage or temperature from sensors that monitor the current path conducted through the motor starter, and the central control unit can deduce from the measured values ​​whether acceptable operating conditions exist in the current path, so that electrical energy can be conducted to the motor via the current path and the switching element, or whether unacceptable operating conditions exist, such as a short circuit or a long-lasting overload, so that the conduction of current through the current path must be interrupted by means of the switching element. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an improved switch device.

[0005] According to the invention, this object is achieved by a switching device having the features specified in claim 1. Furthermore, according to the invention, this object is achieved by a method having the features specified in claim 9.

[0006] The switchgear has two or more current paths, through which energy feeding for downstream loads can be realized. The switchgear can be, for example, a motor starter, a soft starter or a contactor. The load can have inductive characteristics, such as a motor, resistive characteristics, such as an electric heater, or capacitive characteristics, such as a rectifier. The current path conducts the load current set for the electric load from the connection device on the grid side of the switchgear through the switchgear to the connection device on the load side of the switchgear. An electronic interruption unit and a mechanical switch are respectively arranged in series in the current paths, that is, the current for supplying power to the load is guided not only via the electronic interruption unit but also via the mechanical switch. Preferably, the electronic interruption unit is associated with the connection device on the grid side, and the mechanical switch is associated with the connection device on the load side.

[0007] An electronic interruption unit is an electronic switch which implements the functionality of an electromechanical switch, but which has no movable parts. The electronic interruption unit can be switched by means of a semiconductor-based switching element into a high-ohmic state of the switching element for preventing a current flow or into a low-ohmic state of the switching element for a current flow in a current path; for this purpose, semiconductor-based switching elements such as field effect transistors (FETs), MOSFETs (silicon, gallium nitride, silicon carbide), IGBTs, bipolar transistors or diodes are used. In addition to the semiconductor switch, the electronic interruption unit also has a protective element for the semiconductor switch.

[0008] A mechanical switch (also referred to as: mechanical disconnecting contact unit) is an electromechanical switch which can be switched into a current blocking state by opening contacts to prevent current flow in the current path or into a current conducting state by closing contacts for current flow in the current path. A mechanical switch is a mechanical disconnecting contact system, in particular with disconnecting characteristics according to the relevant standards for low-voltage circuits (voltages up to 1000 volts AC or up to 1500 volts DC), wherein the contacts of the mechanical disconnecting contact system are connected in series with an electronic interruption unit. The mechanical switch can be designed, for example, as a relay.

[0009] The current paths are each assigned to a decentralized control unit which is designed to drive the electronic interruption unit; the switching state (current conduction or current blocking) of the electronic interruption unit is therefore controlled by the associated decentralized control unit.

[0010] The switchgear according to the invention can be connected to a power supply line of an electrical load and is used for switching and / or protecting the electrical load; therefore, the switchgear according to the invention can also be referred to alternatively as a switch and protection device. Protecting the electrical load by means of the switchgear serves to protect the electrical load and the power supply line to the electrical load from inadmissibly high currents. The power supply line of the electrical load is an electrical conductor, via which the load is supplied with electrical energy. Examples of applications of the switchgear are applications as power switches, contactors, relays and motor starters, that is to say switching devices for starting motors.

[0011] The method according to the invention is used to operate a switchgear having two or more current paths, through which energy is fed to downstream loads. In this case, electronic interruption units and mechanical switches are arranged in series in each current path. The method comprises driving the electronic interruption units of the current paths by means of decentralized control units assigned to the current paths.

[0012] The invention is based on the recognition that a multi-controller architecture for electronic switches and protective devices, i.e. switches and protective devices equipped with electronic interrupting units, offers advantages with regard to short-circuit protection: since the current values ​​and / or voltage values ​​from which a short circuit is detected are not first transmitted via long transmission paths to a central control unit and the switching command must be transmitted from there back to the electronic interrupting unit again, but rather the current values ​​and / or voltage values ​​are analyzed and the switching command is generated in a decentralized control unit (which is physically arranged in the vicinity of the current / voltage sensors and the electronic interrupting unit and can be reached via short transmission paths), a switching reaction to an occurring danger (such as a short circuit or an overload) can be realized significantly faster than before.

[0013] By distributing control functions over multiple decentralized control units, smaller and less expensive control units can be used than in an architecture with a single central control unit. By cleverly dividing the functions between the central control unit and the decentralized control units, it is also possible to use controllers with lower performance than a single-controller solution.

[0014] In the event of a failure of a decentralized control unit, the central control unit assumes control of the electronic interruption unit associated with the failed decentralized control unit. If a decentralized control unit detects a sensor failure, the decentralized control unit sends a disconnection command directly to the associated electronic interruption unit in order to end the unsafe operating state as quickly as possible. In addition, the decentralized control unit reports the presence of a fault in the sensor to the central control unit, which then triggers actions in other decentralized control units.

[0015] This embodiment of a switchgear with decentralized control units per current path can be referred to as a "multi-controller" architecture; such an architecture is the core of the present invention. It serves as the basis for a modular structure both in terms of HW development and in terms of FW development (FW=Firmware, HW=Hardware). For example, it can be used for three-phase motor starters or (3+N) infrastructure switches.

[0016] The invention provides a switching device which provides short-circuit resistance for very high grid connection powers, short-circuit protection for very high current increases, and is flexible in terms of extending protection and measuring functions. In particular, a decentralized control unit enables a flexibly adjustable short-circuit limit for each phase or each current path.

[0017] Advantageous embodiments and developments of the invention are specified in the dependent claims.

[0018] According to a preferred design of the present invention, the switchgear has a central control unit, which is configured to communicate with decentralized control units for coordinating electronic interruption units and mechanical switches in two or more current paths. This has the advantage that the central control unit obtains information about measured values ​​in the current paths and the switching states of the electronic interruption units from the decentralized control units, and based on this information, can send additional switch-on or switch-off commands to the decentralized control units as necessary.

[0019] According to a preferred embodiment of the invention, the central control unit is constructed as a separate physical electronic component of the switchgear. This has the advantage that the firmware running in the decentralized control units can be identical and therefore different runtimes of algorithms for processing the firmware are not possible.

[0020] According to a preferred design of the present invention, the central control unit is integrated into at least one of the decentralized control units in the form of a firmware component (English: Firmware Stack). The FW component provides all functions of the central control unit for phase coordination, that is, for coordinating electronic interruption units and mechanical switches in two or more current paths of the switchgear. The advantage here is that hardware is saved, that is, a separate physical electronic device for the central control unit.

[0021] The central control unit is provided as a separate controller or as a FW component, which is run on one of the decentralized control units. The central control unit then receives all information about the measured variables and states in the respective other current paths and can then, if necessary, send switch-on or switch-off commands to the other decentralized control units.

[0022] The central control unit sends information, such as switching commands, parameter sets, commands for activating additional functions, to the decentralized control units and receives information, such as measured values, fault states, parameter sets, from the decentralized control units. The central control unit can be designed to activate the voltage supply of the decentralized control units.

[0023] According to a preferred design of the present invention, sensors are respectively provided for the current paths, and the sensors are used to measure the current intensity in the current path and / or the voltage in the current path relative to the reference voltage of another current path, wherein the sensors are configured so that the measured values ​​can be transmitted to a decentralized control unit associated with the current path. To this end, the sensors can have an interface for wired or wireless transmission. Here, the advantage is that the current operating conditions in the current path and the state of the energy feed for the downstream load can be collected.

[0024] According to a preferred embodiment of the present invention, the switch device has an interface for parameterizing the switch device. This has the advantage that the switch device can be simply parameterized by wire or wirelessly via an external parameterization device.

[0025] According to a preferred design solution of the present invention, the decentralized control units communicate directly with each other. In other words, the decentralized control units are configured to communicate with each other. For example, two digital signals (input and output) can be exchanged, i.e. sent and received, between two decentralized control units. For example, information about the zero crossing of the current in a decentralized control unit can be transmitted to one or more of the other decentralized control units. Direct communication can be performed in different ways.

[0026] The first possibility is data communication via a bus system, for example when using SPI (=Serial Peripheral Interface) or a serial interface, for example when using UART (=Universal Asynchronous Receiver Transmitter), to exchange information such as measured variables and states of decentralized control units in the form of binary strings without involving a central control unit. This information exchange is necessary, for example, when implementing central control functions in decentralized control units in the form of firmware modules.

[0027] In the second possibility, only a digital single signal with a rising edge, a falling edge and a duration of a signal level is transmitted as an information carrier. In these digital signals generated by the decentralized control units, information can be encoded into a rising edge, a falling edge and a duration of a signal level. Which information, such as an overcurrent fault, an overload fault, and a current zero crossing are associated with the corresponding signal can be predetermined by the central control unit in a coding rule, and the coding rule is provided to the decentralized control unit. As an example, the current zero crossing recognition in one of the decentralized control units is mentioned here. If the current zero crossing is recognized, the level of the digital signal changes from low to high, or from high to low. This signal is collected by other decentralized control units and can be triggered by the decentralized control units accordingly. The information of the zero crossing in the decentralized control unit may be important for other decentralized control units. The transmission system for transmitting digital signals through digital signal lines between decentralized control units avoids the delay that may occur in the bus system due to the processing of communication media and information.

[0028] According to a preferred design of the present invention, an insulation barrier is formed between every two current paths. This has the advantage of improving electrical safety.

[0029] According to a preferred design of the present invention, the decentralized control units each have a configurable analog module. The analog module may be, for example, a comparator or an operational amplifier. These analog modules integrated into the decentralized control units can be configured by firmware, which can reduce the complexity of the externally required hardware. The advantage of this design of the present invention is that it ensures high flexibility and simplifies the manufacture and maintenance of the switchgear.

[0030] According to a preferred design of the present invention, the decentralized control unit, the electronic interruption unit and the sensor form a protection and measurement module, and the decentralized control unit, the electronic interruption unit and the sensor are respectively associated with a current path. Such a module can also be called a protection and measurement unit (English: Protection and Measurement Cell). This type of module can also assume other functions in addition to short-circuit protection:

[0031] Shunt-based current measurement with a very high bandwidth of >500 kHz: For this purpose, the module can have a shunt for measuring the current in the current path. As a result, the switching device can detect a short circuit relatively quickly and react thereto.

[0032] Measuring the mains voltage between the two current paths and measuring the switching voltage present at the electronic interruption unit: For this purpose, the module can have one or more voltage measuring devices for measuring the voltage. This makes it possible to detect short circuits. The central control unit can infer the voltage present at the load side of the control device from the parameters of the mains voltage and the switching voltage; this information can be used, for example, when restarting the motor.

[0033] Providing the measured values ​​via a communication interface of the module. For this purpose, the module can have a communication interface. The measured values ​​can be provided to the central control unit via the communication interface.

[0034] The core of the protection and measurement module is the decentralized control unit, i.e. the controller that can implement the protection and additional functions. The decentralized control units of the protection and measurement modules or switchgear are coordinated by the superimposed controller, i.e. the central control unit. The actions of the decentralized control units can be triggered by the central control unit via the communication connection and communication interface, e.g. switching on power semiconductors, implementing diagnostic functions, etc. In addition, measured values ​​and states can also be transmitted from the decentralized control units to the central control unit via the communication connection and communication interface.

[0035] According to a preferred design of the present invention, the method has the following steps: measuring the current intensity and / or voltage in the current path; sending the measured value to a decentralized control unit associated with the current path; sending a control instruction to the electronic interruption unit of the current path based on the measured value measured in the current path. Here, the advantage is that the current operating conditions in the current path and the state of energy feeding of the downstream load can be collected.

[0036] According to a preferred design of the present invention, the switchgear has a signal line, through which the decentralized control units or the protection and measurement modules can be synchronized, for example, for sampling the measured values ​​in all the protection and measurement modules at the same time. To this end, the switchgear can have a signal line specially provided for this purpose, or the synchronization signal required for synchronization can be sent through the communication connection between the central control unit and the decentralized control units that already exists.

[0037] According to a preferred design solution of the present invention, the central control unit sends a synchronization signal to the decentralized control units, whereby the decentralized control units can be synchronized. Through the synchronization signal received by the decentralized control units, the decentralized control units can synchronize their calculation steps and / or actions with each other, thereby ensuring that the calculation steps and / or actions are performed simultaneously. The synchronization accuracy of the decentralized control units can be in the nanosecond range. The calculation steps can involve the execution of an algorithm, which is run on the decentralized control units, for example, in the form of a computer program. The action includes switching the electronic interrupt unit at the switching time point and sampling the analog peripheral device at the sampling time point. The synchronization signal can be composed of the falling edge and / or the rising edge of the digital signal.

[0038] According to a preferred design of the present invention, the method has the following steps: sending information about measured values ​​and control commands from decentralized control units to a central control unit of a switchgear; and coordinating electronic interruption units and mechanical switches in two or more current paths by the central control unit based on the received information. The advantage here is that the central control unit obtains all information about measured variables and states in the corresponding other current paths, and can send switch-on or switch-off commands to other decentralized control units when necessary. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The invention is explained below with the aid of the accompanying drawings. In the drawings, the following are schematically and not to scale:

[0040] Figure 1 A typical circuit arrangement of a switchgear is shown;

[0041] FIG2 shows a schematic structure of a known switchgear;

[0042] Figure 3 shows a schematic structure of a switchgear according to the present invention;

[0043] Figure 4 The design of the switchgear according to the present invention is shown;

[0044] Figure 5 A flow chart showing short circuit disconnection;

[0045] Figure 6 An example of a short circuit disconnect is shown;

[0046] Figure 7 A flow chart of the connection according to operation is shown;

[0047] Figure 8 A flow chart showing a first mode of switching on according to operation; and

[0048] Fig. 9 A flow chart showing another mode of switching on according to operation;

[0049] Fig.10 A design scheme for direct communication via a bus system is shown; and

[0050] Fig.11 A design scheme for direct communication via digital signals is shown. DETAILED DESCRIPTION

[0051] Figure 1The typical circuit arrangement of a switchgear 1 is shown, which is arranged in a three-phase power supply line 51, 52, which is divided into a grid-side power supply line 51 and a load-side power supply line 52, through which electrical energy is conducted from a power supply grid 50 having three external conductors L1, L2, L3 to an electrical load 53, such as an electric motor or an electric heating device. The switchgear 1 has grid-side connecting devices 131, 231, 331 and load-side connecting devices 132, 232, 332, by means of which the switchgear 1 is connected to the power supply lines 51, 52.

[0052] FIG. 2 schematically shows the internal structure of a conventional switchgear 1, which can be used in Figure 1 In the circuit arrangement shown. The switchgear 1 has three current paths 13, 23, 33, through which one of the outer conductors L1, L2, L3 of the three-phase power supply network 50 can be respectively guided. For this purpose, the switchgear 1 has a network-side connection device 131, 231, 331, such as a screw terminal or a spring-loaded terminal, whereby the network-side ends of the current paths 13, 23, 33 can be electrically connected to the network-side power supply line 51 of the power supply network 50. In addition, the switchgear 1 has a load-side connection device 132, 232, 332, such as a screw terminal or a spring-loaded terminal, whereby the load-side ends of the current paths 13, 23, 33 can be electrically connected to the load-side power supply line 52 of the load 53.

[0053] An electronic interruption unit 11, 21, 31 and a mechanical switch 12, 22, 32 are arranged in series in each of the current paths 13, 23, 33, wherein a current having a current direction from the grid-side connection device 131, 231, 331 to the load-side connection device 132, 232, 332 first flows through the electronic interruption unit 11, 21, 31 and then through the mechanical switch 12, 22, 32. A current sensor and / or a voltage sensor 41, 42, 43 is arranged in each of the current paths 13, 23, 33 between the grid-side connection device 131, 231, 331 and the electronic interruption unit 11, 21, 31, which is suitable for measuring a current I and / or a voltage U in the current path 13, 23, 33.

[0054] The switchgear 1 has a central control unit 2 equipped with a processor 3, which can receive the measured values ​​of current sensors and / or voltage sensors 41, 42, 43 via data lines 410, 420, 430 and send switching commands to electronic interruption units 11, 21, 31 via communication connections 14, 24, 34 and to switch locks 15 acting on mechanical switches 12, 22, 32 via control lines 16. The measured values ​​of the current and / or voltage sensors 41, 42, 43 can be present as analog signals or as digital data. The data lines 410, 420, 430 are understood here to be any transmission means, not only transmission lines, such as cables, but also wireless transmission means, such as NFC (=Near Field Communication), Bluetooth, WLAN (=Wireless Local Area Network).

[0055] The control unit 2 can analyze the measured values ​​of the received current and / or voltage sensors 41, 42, 43, and determine based on the analysis whether the current value and / or voltage value is in a normal and normal range or in an unacceptable range, such as an overload range, a short circuit range, etc. The control unit 2 can set the current blocking state or the current conducting state of the electronic interruption unit 11, 21, 31 and the mechanical switch 12, 22, 32 respectively through corresponding switching instructions. In normal operation, the control unit 2 can switch the power supply to the load through corresponding switching instructions. For example, when interrupting the current path in normal operation, an undesirable arc between the contacts of the mechanical switch can be avoided in the following manner, that is, the electronic interruption unit is first switched to current blocking, and the mechanical switch is only disconnected afterwards. If the current value and / or voltage value is in an unacceptable range, the switch device 1 can protect the load connected downstream of the switch device 1 from damage by interrupting the current path through corresponding switching instructions.

[0056] The control unit 2 can be parameterized by wire or wirelessly. One or more parameters of the control unit 2 can also be adjusted by a potentiometer of the control unit 2 .

[0057] Figure 3 The schematic structure of a switchgear 100 according to the invention is shown in relatively small detail, and the switchgear can be used in applications such as Figure 1In the circuit arrangement shown. Compared to the conventional switchgear 1 shown in FIG. 2 , the switchgear 100 according to the invention is characterized in that each electronic interruption unit 11, 21, 31 is associated with a decentralized control unit 111, 211, 311. In the embodiment shown, in addition to the decentralized control units 111, 211, 311, the switchgear 100 also has a central control unit 200, which performs coordination between the decentralized control units 111, 211, 311. Therefore, in addition to the decentralized control units 111, 211, 311, Figure 3 The structure of the switchgear 100 according to the present invention shown in FIG. 2 is similar to the structure of the conventional switchgear 1 shown in FIG. 2 ; Figure 1 The circuit arrangement shown in FIG. 1 is just as possible with a conventional switching device 1 using the switching device 100 according to the invention.

[0058] The switchgear 100 has three current paths 13, 23, 33, through which one of the outer conductors L1, L2, L3 of the three-phase power supply network 50 can be respectively conducted. For this purpose, the switchgear 1 has a mains-side connection device 131, 231, 331, such as a screw terminal or a spring-loaded terminal, by which the mains-side ends of the current paths 13, 23, 33 can be electrically connected to the connecting line 51 of the power supply network 50. Furthermore, the switchgear 1 has a load-side connection device 132, 232, 332, such as a screw terminal or a spring-loaded terminal, by which the load-side ends of the current paths 13, 23, 33 can be electrically connected to the connecting line 52 of the load 53.

[0059] An electronic interruption unit 11, 21, 31 and a mechanical switch 12, 22, 32 are arranged in series in each of the current paths 13, 23, 33, wherein a current having a current direction from the grid-side connection device 131, 231, 331 to the load-side connection device 132, 232, 332 first flows through the electronic interruption unit 11, 21, 31 and then through the mechanical switch 12, 22, 32. A current sensor and / or a voltage sensor 41, 42, 43 is arranged in each of the current paths 13, 23, 33 between the grid-side connection device 131, 231, 331 and the electronic interruption unit 11, 21, 31, which is suitable for measuring the current I and / or the voltage U in the current path 13, 23, 33.

[0060] Each of the electronic interruption units 11, 21, 31 is associated with a decentralized control unit 111, 211, 311, respectively. The decentralized control unit 111, 211, 311 receives the measured values ​​of the current and / or voltage sensors 41, 42, 43 via data lines 410, 420, 430 and sends a switching command to the electronic interruption unit 11, 21, 31 via a communication connection 116, 216, 316. The measured values ​​of the current and / or voltage sensors 41, 42, 43 can be present as analog signals or as digital data. The data lines 410, 420, 430 are understood here to be any transmission means, not only transmission lines, such as cables, wires, but also wireless transmission means, such as NFC, Bluetooth, WLAN. The switching command can be a simple digital signal (with two different states: low-high).

[0061] The decentralized control unit 111, 211, 311 can analyze the received measured values ​​of the current and / or voltage sensors 41, 42, 43 and determine based on the analysis whether the current value and / or voltage value is in a normal and conventional range or in an unacceptable range, such as in an overload range, a short circuit range, etc. The decentralized control unit 111, 211, 311 can adjust the current blocking state or the current conducting state of the electronic interruption unit 11, 21, 31 respectively by corresponding switching commands. In normal operation, the decentralized control unit 111, 211, 311 can switch the power supply to the load by corresponding switching commands. For example, when interrupting the current path in normal operation, an undesirable arc between the contacts of the mechanical switch can be avoided by first switching the electronic interruption unit 11, 21, 31 to current blocking and then opening the mechanical switch 12, 22, 32. If the current value and / or voltage value is in an unacceptable range, the switch device 100 can protect the load connected downstream of the switch device 100 from damage by interrupting the current path by corresponding switching commands.

[0062] Furthermore, the switchgear 100 has a central control unit 200 equipped with a processor 201. The central control unit 200 is connected to the decentralized control units 111, 211, 311 via communication connections 140, 240, 340; in this way, the central control unit 200 can coordinate the control behavior of the decentralized control units 111, 211, 311 via control commands.

[0063] The central control unit 200 communicates individually with each decentralized control unit 111, 211, 311. The communication is used on the one hand for information transmission and on the other hand for synchronizing all decentralized control units 111, 211, 311, so that all electronic interruption units 11, 21, 31 can be switched in a coordinated manner if necessary.

[0064] According to an alternative design, it can also be provided that the decentralized control units 111, 211, 311 communicate directly with each other. For example, two digital signals (input and output) can be exchanged between the decentralized control units 111, 211, 311, that is, two digital signals are sent and received. For example, information about the zero crossing of the current in a decentralized control unit can be transmitted to one or more of the other decentralized control units.

[0065] according to Figure 3 In the first design scheme shown in FIG, the mechanical switches 12, 22, 32 are not driven by the decentralized control units 111, 211, 311, but by the central control unit 200. For this purpose, the central control unit 200 sends control instructions to the switch lock 150 acting on the mechanical switches 12, 22, 32 via the control line 160.

[0066] According to an alternative design, the mechanical switches 12, 22, 32 are driven by decentralized control units 111, 211, 311. In this case, the central control unit 200 sends a switching command to the decentralized control units 111, 211, 311 via the communication connection 140, 240, 340, which is to cause the mechanical switches 12, 22, 32 to be switched. The decentralized control units 111, 211, 311 in turn send the control command to the switch lock 150 or directly to the switch actuator of the corresponding mechanical switch 12, 22, 32.

[0067] One variant of the switchgear 100 is to transfer one or more functions of the central control unit 200 to one of the decentralized control units 111, 211, 311. For this purpose, the functions can be integrated as software components into one of the decentralized control units 111, 211, 311. The coordination function can also be designed in a decentralized manner, for example integrated in one or more of the decentralized control units 111, 211, 311. The coordination function can be designed as a software component, for example firmware.

[0068] The control unit 2 can be parameterized either wired or wirelessly.

[0069] Figure 4The embodiment of the switchgear 100 according to the invention is shown in a relatively high degree of detail. The switchgear 100 has three current paths 13, 23, 33, through which one of the outer conductors L1, L2, L3 of the three-phase power supply network 50 can be respectively conducted. For this purpose, the switchgear 100 has a network-side connection device 131, 231, 331, such as a screw terminal or a spring-loaded terminal, by which the network-side ends of the current paths 130, 230, 330 can be electrically connected to the connecting line 51 of the power supply network 50. In addition, the switchgear 100 has a load-side connection device 132, 232, 332, such as a screw terminal or a spring-loaded terminal, by which the load-side ends of the current paths 13, 23, 33 can be electrically connected to the connecting line 52 of the load 53.

[0070] In each of the current paths 13, 23, 33, a protection and measurement module 170, 270, 370 and a mechanical switch 12, 22, 32 are respectively arranged in series, wherein a current having a current direction from the connecting device 131, 231, 331 on the grid side to the connecting device 132, 232, 332 on the load side first flows through the protection and measurement module 170, 270, 370 and then flows through the mechanical switch 12, 22, 32.

[0071] The protection and measuring modules 170, 270, 370 each have a grid-side connection device 123, 223, 323 and a load-side connection device 124, 224, 324, whereby the protection and measuring modules 170, 270, 370 are connected to the current paths 13, 23, 33. The grid-side connection device 123, 223, 323 and the load-side connection device 132, 232, 332 are electrically connected to each other via a load current line 130, 230, 330. The protection and measuring modules 170, 270, 370 each have a current sensor 114, 214, 314 for measuring a current I in the load current line 130, 230, 330 and an electronic interruption unit 11, 21, 31, which is connected in series in the load current line 130, 230, 330.

[0072] The protection and measurement modules 170, 270, 370 each have a decentralized control unit 111, 211, 311, which is respectively associated with an electronic interruption unit 11, 21, 31 of the protection and measurement modules 170, 270, 370. The decentralized control unit 111, 211, 311 receives the measured values ​​of the current sensors 114, 214, 314 via data lines 115, 215, 315 and sends switching commands to the electronic interruption units 11, 21, 31 via communication connections 116, 216, 316. The decentralized control units 111, 211, 311 can analyze the received measured values ​​of the current sensors 41, 42, 43 and determine based on the analysis whether the current value is in a normal and conventional range or in an unacceptable range, for example in an overload range, a short circuit range, etc. The decentralized control units 111, 211, 311 can adjust the current cutoff state or current conduction state of the electronic interruption units 11, 21, 31 respectively through corresponding switching instructions. In normal operation, the decentralized control units 111, 211, 311 can switch the power supply to the load through corresponding switching instructions. For example, when interrupting the load current line 130, 230, 330 in normal operation, the undesirable arc between the contacts of the mechanical switch can be avoided in the following manner, that is, the electronic interruption unit current is first switched to current cutoff and the mechanical switch is disconnected only afterwards. If the current value and / or the voltage value are within an unacceptable range, the switch device 100 can protect the load close to the switch device 100 from damage by interrupting the current path through corresponding switching instructions.

[0073] The switchgear 100 also has a central control unit 200 equipped with a processor 201. The central control unit 200 is connected to the protection and measuring modules 170, 270, 370 via communication connections 140, 240, 340. The protection and measuring modules 170, 270, 370 have interfaces 112, 212, 312, which receive signals arriving from the central control unit 200 and transmit signals from the protection and measuring modules 170, 270, 370 to the central control unit 200. For this purpose, the interfaces 112, 212, 312 are connected to the corresponding decentralized control units 111, 211, 311 via communication connections 117, 217, 317, respectively. In this way, the central control unit 200 can coordinate the control behavior of the decentralized control units 111, 211, 311 by means of control commands; on the other hand, the data and information required by the central control unit 200 for its coordination tasks can be transmitted from the protection and measuring modules 170, 270, 370 to the central control unit 200, respectively.

[0074] In addition, the central control unit 200 can send control instructions to the switch lock 150 acting on the mechanical switches 12 , 22 , 32 through the control line 160 .

[0075] The control unit 2 can be parameterized either wired or wirelessly.

[0076] Figure 5 A flow chart for short-circuit disconnection in a switching device according to the present invention is shown. A first step 501 marks a state in which current flows in one of a plurality of current paths of a switching device according to the present invention (hereinafter referred to as a "current path"). In step 502, a current sensor determines a measured value of the current intensity of the current flowing in the current path and sends the current measurement value to a decentralized control unit associated therewith. Additionally, a voltage sensor determines a voltage measurement value of the voltage applied to the current path and likewise sends the measured voltage measurement value to a decentralized control unit associated therewith. In step 503, the decentralized control unit receives the measured current measurement value and the voltage measurement value from the sensor. In step 504, the decentralized control unit compares the current measurement value with an allowed value range or a current limit value I lim Here, two different situations are now considered: In a first situation 1, the decentralized control unit determines in step 505 that the current measurement value is within the permissible value range or below the current limit value I lim Therefore, the measuring cycle ends in step 506 with the result that no action is required and the next measuring cycle is awaited.

[0077] In the second case 2, the decentralized control unit determines in step 507 that the current measurement value is above the permitted value range or above the current limit value I lim (trigger threshold). Therefore, the decentralized control unit determines that there is a short circuit. In step 508, the decentralized control unit directly provides a disconnection instruction to the electronic interruption unit connected to the current path without delay in order to end the short circuit as quickly as possible. In step 509, the electronic interruption unit triggered by the received disconnection instruction changes to the current blocking state. In step 510, the decentralized control unit reports the following information to the central control unit: a short circuit is detected in the current path and a disconnection instruction is sent to the electronic interruption unit connected to the current path. In step 511, the central control unit triggers the action of other decentralized control units, for example, changing the electronic interruption unit in the other current paths connected to the switch device to the current blocking state. Therefore, the central control unit coordinates the disconnection of the electronic interruption units in the other current paths 13, 23, 33 and preferably also coordinates the disconnection of the mechanical switch.

[0078] A similar method sequence can also be carried out for asymmetry detection. In the case of symmetrical loads, the sum of the currents in the current paths (phases) is approximately equal to zero. In unbalance detection, the current intensities in all current paths are measured, added and compared to a threshold value band: the sum of the measured values ​​should lie in a value band of +-x amperes around zero. A typical value is x=2, where this value can be set (parameterized) on the switching device. If the sum of the measured values ​​lies within the threshold value band, no action is required. However, if the sum of the measured values ​​lies outside the threshold value band, this is identified as an asymmetry and a disconnection command is sent to a decentralized control unit, which then causes a current cutoff switch of the electronic interruption unit.

[0079] Figure 6 An example of short circuit disconnection in a switching device according to the invention is shown. The upper part of the figure shows the current intensity I SW and grid voltage U GR The middle part of the figure shows the time curve of the gate signal S G The lower part of the figure shows the output signal S of the current comparator. C The current comparator measures the current intensity I present in the current path of the switching device as a function of the time curve. SW With the current limit value I lim Make a comparison.

[0080] At the time t0 when the sinusoid of the grid voltage has a zero crossing and the voltage cycle begins, current flows through the current path of the switching device; this is achieved in that the electronic interruption unit connected to the current path is in a current-conducting state, just like a mechanical switch connected in series with the electronic interruption unit (however, this mechanical switch is not considered further here). The electronic interruption unit has a semiconductor switch with a gate, such as a transistor or a thyristor; depending on the drive of the gate, the electronic interruption unit can be placed in a current-conducting operating state or a current-blocking operating state. At the time t0, the electronic interruption unit is in a current-conducting state because a control signal S is applied to the gate. G >0.

[0081] At the time t1>t0, a short circuit is triggered in the current path (phase) under consideration. SW Then it increases for a long time until the time t2>t1 exceeds the predefined current limit value I lim . Current limit value I lim The excess is detected by a comparator which continuously checks the current intensity I SWWhether the current limit value I is exceeded lim At the time point t2, the comparator output signal S C From the value S C =0 becomes value S C >0.

[0082] The decentralized control unit associated with the observed current path directly supplies a disconnection command to the electronic interruption unit connected to the current path without delay. The electronic interruption unit is triggered by the disconnection command to change from the current conducting state to the current blocking state by the gate signal S G From the value S G >0 transforms to value S G = 0. Therefore, the current in the current path decays to 0 A and the short circuit is extinguished.

[0083] Figure 7 The flow chart of the operation-dependent disconnection in the switchgear according to the invention is shown. In step 701, the central control unit sends a disconnection command to the decentralized control units. In step 702, after receiving the disconnection command, the decentralized control units wait with a hysteresis of +-0.5 A (parameterized) which can be set until the current is approximately 0 A. In step 703, the decentralized control units provide the disconnection command to the electronic interruption unit.

[0084] Figure 8 A flow chart of a first mode of switching on according to operation in a switchgear according to the invention is shown. In a first step 801, the central control unit sends a switching on command to the decentralized control units. In step 802, after receiving the switching on command, the decentralized control units immediately send the switching on command to the electronic interruption units.

[0085] Fig. 9 A flow chart of alternative modes of switching on according to operation in a switching device according to the invention is shown. In a first step 811, the central control unit sends the voltage phase angle to be switched on to the decentralized control unit. In step 812, the decentralized control unit evaluates the input voltage applied to the input terminals of the switching device and, when the voltage phase angle is reached, provides a switch-on command to the electronic interruption unit.

[0086] Fig.10 Another embodiment of a switchgear 100 according to the present invention is shown. Figure 4 All features of the switchgear shown in FIG. Fig.101 , the mechanical switches 12, 22, 32 are not shown, but additionally have a bus-based communication system (short for: bus system) with a bus line 5 between the protection module and the measuring module 170, 270, 370, which each have a decentralized control unit 111, 211, 311. Data communication is carried out via the bus system, for example by using an SPI or a serial interface, for example a UART, for exchanging information, for example measured variables and states of the decentralized control units 111, 211, 311, in the form of binary strings, without involving the central control unit 200. This information exchange is necessary, for example, when a central control function is implemented in the form of a firmware component in the decentralized control units 111, 211, 311.

[0087] Fig.11 Another embodiment of a switchgear 100 according to the present invention is shown. Figure 4 All features of the switchgear shown in FIG. Fig.11 1, mechanical switches 12, 22, 32 are not shown in the figure, but additionally there is a transmission system for transmitting digital signals between the protection modules and the measuring modules 170, 270, 370 via digital signal lines 6, 7, 8, which have decentralized control units 111, 211, 311 respectively. The first digital signal line 6 is used for signal transmission from the decentralized control unit 111 of the first protection and measuring module 170 to the decentralized control units 211, 311 of the second and third protection and measuring modules 270, 370. The second digital signal line 7 is used for signal transmission from the decentralized control unit 211 of the second protection and measuring module 270 to the decentralized control units 111, 311 of the first and third protection and measuring modules 170, 370. The third digital signal line 8 is used for signal transmission from the decentralized control unit 311 of the third protection and measuring module to the decentralized control units 111, 211 of the first and second protection and measuring modules 170, 270.

[0088] Through the digital signal lines 6, 7, 8, only a digital single signal with a rising edge, a falling edge and a duration of a signal level is transmitted as an information carrier. In these digital signals generated by the decentralized control units 111, 211, 311, information can be encoded into the rising edge, the falling edge and the duration of the signal level. Which information, such as an overcurrent fault, an overload fault, and a current zero crossing are associated with the corresponding signal can be predetermined by the central control unit 200 in a coding rule, and the coding rule is provided to the decentralized control units 111, 211, 311. As an example, the current zero crossing recognition in one of the decentralized control units 111, 211, 311 is mentioned here. If the current zero crossing is recognized by one of the decentralized control units 111, 211, 311, the decentralized control unit 111, 211, 311 that performs the recognition changes the level of the digital signal from low to high or from high to low. The signal level change is collected by other decentralized control units 111, 211, 311 and can trigger an action accordingly by the decentralized control units 111, 211, 311. The information about the zero crossings of the decentralized control units 111, 211, 311 can be relevant to other decentralized control units 111, 211, 311. The transmission system for transmitting digital signals between the decentralized control units 111, 211, 311 via the digital signal lines 6, 7, 8 avoids delays that can occur in a bus system due to the processing of the communication medium and the information.

Claims

1. A switching device (100) having two or more current paths (13, 23, 33), through which energy can be fed to a downstream load (53), wherein: An electronic interruption unit (11) and a mechanical switch (12) are respectively arranged in series in the current paths (13, 23, 33). It is characterized in that The current paths (13, 23, 33) are respectively associated with a decentralized control unit (111, 211, 311), which is designed to drive the electronic interruption unit (11, 21, 31).

2. The switchgear (1) according to claim 1, A central control unit (200) is provided, which is designed to communicate with the decentralized control units (111, 211, 311) in order to coordinate the electronic interruption units (11, 21, 31) and the mechanical switches (12, 22, 32) in the two or more current paths (13, 23, 33).

3. The switchgear (1) according to claim 2, in, The central control unit (200) is designed as a separate physical electronic component of the switch device (100) or is integrated into at least one of the decentralized control units (111, 211, 311) in the form of a firmware component.

4. The switchgear (100) according to any one of the preceding claims, in, The current paths (13, 23, 33) are respectively associated with sensors (41, 42, 43) for measuring the current intensity in the current paths (13, 23, 33) and / or measuring the voltage in the current paths (13, 23, 33) relative to a reference voltage of another current path (13, 23, 33), wherein the sensors are designed so that the measured values ​​can be transmitted to a decentralized control unit (111, 211, 311) associated with the current paths (13, 23, 33).

5. The switchgear (100) according to any one of the preceding claims, wherein: The decentralized control units (111, 211, 311) are designed to communicate directly with one another.

6. The switchgear (100) according to any one of the preceding claims, wherein: The decentralized control units (111, 211, 311) each have a configurable analog module.

7. The switchgear (100) according to claim 4, wherein: The decentralized control unit (111, 211, 311), the electronic interruption unit (11, 21, 31) and the sensor (41, 42, 43), each of which is associated with a current path (13, 23, 33), form a module (170, 270, 370).

8. The switchgear (1) according to any one of claims 2 to 7, in, The central control unit (200) is designed to provide a synchronization signal to the decentralized control units (111, 211, 311).

9. A method for operating a switching device (100) having two or more current paths (13, 23, 33) through which energy is fed to a downstream load (53), wherein: An electronic interruption unit (11) and a mechanical switch (12) are respectively arranged in series in the current paths (13, 23, 33). It is characterized by the following steps: The electronic interruption units (12) of the current paths (13, 23, 33) are driven respectively by decentralized control units (111, 211, 311) associated with the current paths (13, 23, 33).

10. The method according to claim 9, in, The central control unit (200) of the switch device (100) sends a synchronization signal to the decentralized control units (111, 211, 311), and the decentralized control units (111, 211, 311) can be synchronized by the synchronization signal.

11. The method according to claim 9 or 10, comprising the steps of: measuring the current intensity and / or the voltage in the current path (13, 23, 33); sending the measured value to a decentralized control unit (111, 211, 311) associated with the current path (13, 23, 33); An electronic interruption unit (11, 21, 31) sends control commands to a current path (13, 23, 33) based on a measured value measured in the current path.

12. The method according to claim 9 or 10, comprising the steps of: sending information about measured values ​​and control commands from the decentralized control units (111, 211, 311) to a central control unit (200) of the switchgear (100); The electronic interruption units (11, 21, 31) and mechanical switches (12, 22, 32) in the two or more current paths (13, 23, 33) are coordinated by the central control unit (200) based on the received information.

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