Fieldbus system for controlling power outputs

Abstract

System (10), comprising: a fieldbus coupler (12), wherein the fieldbus coupler (12) has a first fieldbus interface (16) to a fieldbus (18) and a first subbus interface (20) to a subbus (22); a first module (14a), wherein the first module (14a) has a control interface (26) for connection to a control bus (28), a second subbus interface (24) for communication with the fieldbus coupler (12) and a first control output (30); and a second module (14b), wherein the second module (14b) has a control input and a power output (32); wherein the first module (14a) is set up to derive a control signal from a signal received during operation via the control interface (26) and output it at the first control output (30); and the second module (14b) is set up to control the power output (32) of the second module (14b) in accordance with the control signal received via the control input.

Description

AREA

[0001] The present invention relates to a fieldbus system comprising a fieldbus coupler and connected modules. In particular, the present invention relates to a fieldbus system for controlling power outputs. BACKGROUND

[0002] Fieldbus systems comprising a fieldbus coupler and connected modules are known, for example, from DE 10 2013 105 097 A1. DE 100 20 074 A1 also discloses a modular safety switching device that has output modules to which the loads to be switched are connected. Furthermore, it is known that switching power outputs in telecontrol systems can place increased demands on determinism and response time. SUMMARY

[0003] The invention enriches the state of the art in this respect, as systems according to the invention do not route switching commands for controlling power outputs via the fieldbus coupler, but via a separate module connected to the fieldbus coupler, so that the requirements on the fieldbus coupler with regard to determinism and response time are reduced.

[0004] A system according to the invention comprises a fieldbus coupler, wherein the fieldbus coupler has a first fieldbus interface to a fieldbus and a first subbus interface to a subbus, a first module, wherein the first module has a control interface for connection to a control bus, a second subbus interface for communication with the fieldbus coupler and a first control output, and a second module, wherein the second module has a control input and a power output. The first module is configured to derive a control signal from a signal received during operation via the control interface. The second module is configured to control the power output of the second module in accordance with the control signal received via the control input.

[0005] The term "fieldbus coupler," as used in the description and claims, refers in particular to a device with a fieldbus interface that is configured to transmit status signals via the fieldbus to a higher-level controller and to receive control signals from the higher-level controller. Furthermore, the term "module," as used in the description, refers in particular to a bus terminal configured for connection to a fieldbus coupler, whereby the connection enables a serial mechanical and electrical linking of a plurality of bus terminals.

[0006] Furthermore, the term "subbus," as used in the description and claims, refers in particular to a bus system that connects a plurality of bus terminals and the fieldbus coupler. Furthermore, the term "fieldbus," as used in the description and claims, refers in particular to a bus system via which several fieldbus couplers are connected to the higher-level controller. Furthermore, the term "control bus," as used in the description and claims, refers in particular to a bus system via which control commands are transmitted exclusively or primarily and which has special requirements regarding determinism and response time.

[0007] Furthermore, the term "control input / output," as used in the description and claims, refers in particular to an electrical connection via which a control signal is input or output during operation. Furthermore, the term "power output," as used in the description and claims, refers in particular to an electrical connection via which higher voltages / currents are output than those input via the control input, so that relatively higher voltages / currents can be controlled using relatively low voltages / currents.

[0008] Preferably, the first module has a second control output and is configured to receive configuration data from the fieldbus coupler via the second subbus interface during an initialization routine and to derive from the configuration data an association between signals received during operation via the control interface and control signals to be output via the first and second control outputs.

[0009] Preferably, the second module has a third sub-bus interface for communication with the fieldbus coupler and is configured to transmit data regarding control signals received via the control input and / or voltages and / or currents output at the power output to the fieldbus coupler via the third sub-bus interface.

[0010] Preferably, the second module comprises an interface for querying a state of a device controlled by the second module and is configured to transmit data relating to a queried state to the fieldbus coupler via the third subbus interface.

[0011] Preferably, the first module is configured to initiate a test operation in response to a command from the fieldbus coupler and, with respect to the signals received via the control interface during the test operation, to generate data indicating which control signals are derived from said signals or would be derived during operation, and to transmit the generated data to the fieldbus coupler.

[0012] Preferably, the system further comprises a transformer, wherein the second module is configured to cause the transformer to be disconnected from the mains in response to corresponding signals received via the control interface.

[0013] Preferably, the first module and / or the second module are configured for connection to the fieldbus coupler.

[0014] The control interface is preferably designed as an Ethernet or fiber optic interface.

[0015] Preferably, the first module is configured to receive datagrams via the control interface “Generic Object Oriented Substation Events”, GOOSE.

[0016] A method according to the invention for isolating a transformer from a power supply network using the system comprises sending a disconnection command from a host computer via the control interface to the first module, deriving a control command from the disconnection command and sending the control command via the first control output to the control input of the second module, and switching, by the second module, the power output in response to receiving the control command, wherein the switched power output causes a disconnection of the transformer by means of a load-break switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention is explained below in the detailed description using exemplary embodiments, with reference to drawings in which: Fig. 1 shows a block diagram of a system according to the invention; Fig. 2 to Fig. 5 illustrate the use of the system according to the invention; and Fig. 6 shows a flow diagram of a method according to the invention.

[0018] In the drawings, identical or functionally similar elements are identified by the same reference symbols. DETAILED DESCRIPTION

[0019] Fig. 1 shows a system 10 comprising a fieldbus coupler 12 and modules 14a, 14b (fieldbus terminals) connected to the fieldbus coupler 12. The fieldbus coupler 12 has a first fieldbus interface 16 to a fieldbus 18 and a subbus interface 20 to a subbus 22. The connected modules 14a, 14b also have subbus interfaces 24 to the subbus 22, so that communication can take place between the fieldbus coupler 12 and the modules via the subbus 22. In addition to the subbus interface 24, the first connected module 14a has a control interface 26 for connection to a control bus 28. The control interface 26 can be designed, for example, as an Ethernet or fiber optic interface, via which "Generic Object Oriented Substation Events" (GOOSE) datagrams are received.

[0020] The first module 14a connected in series further comprises a plurality of control outputs 30 and is configured to derive a control signal from a signal received during operation via the control interface 26 and to output it at one of the control outputs 30. A power output 32 of one of the modules 14b connected in series to the first module 14a is controlled via the control signal. Fig. As indicated in Figure 2, the assignment 34 between the signal received via the control interface 26 and a control signal to be output at a control output 30, via which a power output 32 is controlled, can be fixed or configurable. For example, during an initialization routine, configuration data can be provided by the fieldbus coupler 12, and the assignment 34 between the signals received via the control interface 26 and the control signals to be output via the control outputs 30 can be derived from the configuration data.

[0021] If a signal is received via the control interface 26 during operation, the module 14 outputs, as shown in Fig. 3, outputs control signals to the respective control output(s) 30, whereby the power outputs 32 connected to the control outputs 30 can be switched. In addition, as shown in Fig. 4, the first module 14 may be configured to initiate test operation in response to a command from the fieldbus coupler 12 and, with respect to the signals received via the control interface 26 during the test operation, to generate data indicating which control signals are derived from said signals or would be derived during operation, and to transmit the generated data to the fieldbus coupler 12. Thus, during the test operation, the switching of the power outputs 32 can be paused and the functionality of the first module 14 can be checked (during ongoing operation).

[0022] Furthermore, the modules 14b connected to the first module 14a can be configured to transmit data regarding control signals received via the control input and / or voltages and / or currents output at the power output 32 to the fieldbus coupler 12 (for monitoring and / or diagnostic purposes) via the subbus interface 24. Furthermore, the modules 14b can be configured to transmit data regarding the status of the devices controlled by the module 14b to the fieldbus coupler 12 (for monitoring and / or diagnostic purposes). The transmitted data can, for example, be stored in a memory of the fieldbus coupler 12 and queried (cyclically) by a central control unit via the fieldbus 18.

[0023] For example, as in Fig. 5, a module 14b may be used to control a transformer 38 (of a power supply network). If, as in step 42 of the Fig.6, a master computer 40 sends a disconnection command to the first module 14a via the control interface 26, the first module 14a derives a control signal from the disconnection command according to step 44 (according to the assignment 34) and outputs it at the corresponding control output 30. In step 46, the control signal de-energizes the power output 32 of the module 14b. LIST OF REFERENCE SYMBOLS 10 systems 12 fieldbus couplers 14a module (fieldbus terminal) 14b module (fieldbus terminal) 16 fieldbus interface 18 Fieldbus 20 Subbus interface 22 Subbus 24 Subbus interface 26 Control interface 28 Control bus 30 Control output 32 power output 34 Assignment 36 storage 38 Transformer 40 master computers 42 process steps 44 process steps 46 process steps

Claims

[1] System (10) comprising: a fieldbus coupler (12), wherein the fieldbus coupler (12) has a first fieldbus interface (16) to a fieldbus (18) and a first subbus interface (20) to a subbus (22); a first module (14a), wherein the first module (14a) has a control interface (26) for connection to a control bus (28), a second sub-bus interface (24) for communication with the fieldbus coupler (12) and a first control output (30); and a second module (14b), wherein the second module (14b) has a control input and a power output (32); wherein the first module (14a) is configured to derive a control signal from a signal received during operation via the control interface (26) and to output it at the first control output (30); and the second module (14b) is arranged to control the power output (32) of the second module (14b) in accordance with the control signal received via the control input. [2] System (10) according to claim 1, wherein the first module (14a) has a second control output and is configured to receive configuration data from the fieldbus coupler (12) via the second sub-bus interface (24) during an initialization routine and to derive from the configuration data an association (34) between signals received during operation via the control interface (26) and control signals to be output via the first and second control outputs (30). [3] System (10) according to claim 1 or 2, wherein the second module (14b) has a third sub-bus interface (24) for communication with the fieldbus coupler (12) and is configured to transmit data regarding control signals received via the control input and / or voltages and / or currents output at the power output (32) to the fieldbus coupler (12) via the third sub-bus interface (20). [4] System (10) according to one of claims 1 to 3, wherein the second module (14b) comprises an interface for querying a state of a device controlled by the second module (14b) and is configured to transmit data relating to a queried state to the fieldbus coupler (12) via the third subbus interface (24). [5] System (10) according to one of claims 1 to 4, wherein the first module (14a) is arranged to start a test operation in response to a command from the fieldbus coupler (12) and to generate data with respect to the signals received via the control interface (26) during the test operation, which data indicate which control signals are derived from said signals or would be derived during operation, and to transmit the generated data to the fieldbus coupler (12). [6] System (10) according to one of claims 1 to 5, further comprising: a transformer (38); wherein the second module (14a) is configured to cause the transformer (38) to be disconnected from the mains in response to corresponding signals received via the control interface (26). [7] System (10) according to one of claims 1 to 6, wherein the first module (14a) and / or the second module (14b) are configured for connection to the fieldbus coupler (12). [8] System (10) according to one of claims 1 to 7, wherein the control interface (26) is designed as an Ethernet or fiber optic interface. [9] System (10) according to one of claims 1 to 8, wherein the first module (14a) is arranged to receive “Generic Object Oriented Substation Events”, GOOSE, datagrams via the control interface (26). [10] A method of isolating a transformer (38) from a power supply network using a system (10) according to any one of claims 1 to 9, comprising: Sending (42) a disconnection command from a host computer (40) via the control interface (26) to the first module (14a); Deriving (44) a control command from the separation command and sending the control command via the first control output (30) to the control input of the second module (14b); and Switching (46), by the second module (14), the power output (32) in response to receiving the control command; wherein the switched power output (32) causes a separation of the transformer (38) by means of a load-break switch.

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