Intelligent process interface and substation automation system
View Patent ↗This specification discloses an intelligent and digitalized process level interface which is referred to herein as an Intelligent Process Interface (IPI). The input of the IPI includes both analog and digital channels and therefore the IPI can be used for substations in transition or retrofit stages with both conventional and non-conventional primary devices. The IPI acts not only as a digitalized interface, but also as an intelligent supervisory and control unit for switching functions. The architecture of the IPI is flexible and allows for the functionality to be distributed to several devices.
1. An Intelligent Process Interface (IPI) of a Substation Automation (SA) system for a substation of an electric power system, the IPI comprising:
a processing module configured to issue a command signal for operating a switching device of the substation, and to generate and transmit, over a communication network of the SA system, a network message comprising sampled values of a first signal and a second signal, the signals being measured by at least one of an Instrument Transformer (IT) and a sensor connected to the IPI via an input interface, said sampled values being generated and transmitted by the IPI;
wherein the processing module is configured to generate the command signal based on the first signal;
wherein a merging unit comprises current and/or voltage measurement outputs and sensors connected to said merging unit;
wherein said IT and said sensor include a compensation of a total time delay by using a digitally processed synchronization filter;
wherein said total time delay includes the sensor delay and the channel data processing delay; and
wherein said sampled values are synchronized by using two channels in which new samples are formed.
2. The IPI according to claim 1 , wherein the processing module is configured to merge the first and second signals received from at least one of a conventional current or voltage transformer and a non-conventional current or voltage sensor.
3. The IPI according to claim 1 , wherein the processing module is configured to synchronize the first and second signals before generating the network message.
4. The IPI according to claim 1 , wherein the processing module is configured to generate the command signal by executing an intelligent function based on at least one of the first signal and a network message.
5. The IPI according to claim 1 , wherein the processing module is configured to integrate blocking logic on behalf of the switching device.
6. The IPI according to claim 1 , wherein it is adapted to transmit analog signals to a conventional protection relay (CIED).
7. The IPI according to claim 1 , wherein the processing module is configured to merge the first and second signals received from at least one of a conventional current or voltage transformer and a non-conventional current or voltage sensor, and to issue a binary command comprising the command signal.
8. The IPI according to claim 7 , wherein the processing module is configured to synchronize the first and second signals before generating the network message.
9. The IPI according to claim 1 , wherein the processing module is configured to merge the first and second signals received from at least one of a conventional current or voltage transformer and a non-conventional current or voltage sensor, and to generate a command message comprising the command signal.
10. The IPI according to claim 9 , wherein the processing module is configured to synchronize the first and second signals before generating the network message.
11. A Substation Automation (SA) system for a high or medium voltage substation of an electric power system, the SA system comprising:
an Intelligent Electronic Device (IED) configured to perform at least one of protection, control and monitoring functions based on signals being indicative of a process quantity of a substation and originating from at least one of an Instrument Transformer (IT) and a sensor arranged in the substation;
a SA communication network; and
an Intelligent Process Interface (IPI) connected to the IT and sensor via an input interface and connected to a switching device for transmitting a command signal,
wherein the IPI is configured to generate the command signal based on a signal received from at least one of the IT and sensor,
wherein the IPI is configured to generate and transmit, over the SA communication network, a network message comprising sampled values of a first signal and a second signal, the signals being measured, respectively, by the IT and the sensor, and
wherein the IPI further comprises a digital synchronization filter for synchronizing the first and second signals by compensating a total time delay, the total time delay including a channel data processing delay and a delay inherent to, respectively, the IT and sensor.
12. The SA system according to claim 11 , wherein the IPI is configured to generate and transmit, over the communication network of the SA system, a network message comprising sampled values of a first signal and a second signal, the signals being measured by the at least one of the IT and sensor connected to the IPI via the input interface.
13. The SA system according to claim 12 , wherein the IPI comprises an analog input interface configured to be connected to an IT, and a digital input interface configured to be connected to a sensor arranged in the substation via a digital link, and
wherein the SA system comprises:
an Instrument Transformer (IT) hard-wired to the analog input interface of the IPI; and
a sensor arranged in the substation and connected to the digital input interface of the IPI via the digital link.
14. The SA system according to claim 11 , wherein the IPI is arranged at a distance of approximately 2 to 10 meters from the switching device.