FIELD OF INVENTION
[001] The present invention relates to the Auxiliary Bay Control Unit (BCU) for
substation automation systems. More particularly, the invention relates to a system
and method for implementing the IEC 61850 server communication protocol and
realization of measurement, protection, control and recording functionality in
Auxiliary BCU using a real time operating system as well as the manner in which
the modules are assembled in the enclosure.
BACKGROUND OF THE INVENTION
[002] Substation Automation System (SAS) is based on decentralized, bay-oriented
architecture. The architecture is structured on three levels i.e. Station level, Bay
level and Process level. At bay level, Bay Control Units (BCUs) provide all the bay
level functions including control, monitoring and protection, scanning inputs for
status indication and giving outputs as commands. Auxiliary BCUs are directly
connected to operate the switchgear. Data exchange between IEDs and station HMI
(Human Machine Interface) at station level take place on communication
infrastructure. IEC 61850 is an international standard for communication in
substation automation systems. The edition 2 of IEC 61850 was released in 2012 in
order to cover new applications and improve interoperability.
[003] EP2203754B1 titled ‘Operating a Substation Automation System’ relates to a
system and method in which during maintenance, commissioning and fault

situations, when one or several IEDs are inoperable, the data that these IEDs would
have produced is substituted to ensure availability of the substation.
[004] US9136697B2 titled ‘Substation automation system with protection functions’
relates to a Substation Automation (SA) system that is configured to perform
protection functions for a bay of an electrical power distribution substation, receive,
via a communication link, redundancy protection commands from a remote centre,
and execute the redundancy protection commands for the bay.
[005] US8923993B2 titled ‘Method and system for engineering a substation
automation system’ relates to a method for engineering and configuration of one or
more IEDs for a function in a substation automation also includes creating pre-defined
type definitions for an application function, providing a selectable menu for selection
of appropriate parameters with respect to the application. The method includes
creating process configuration outputs for the application function, and configuring
the one or more IEDs based on the process configuration outputs.
[006] US20140025321A1 titled ‘System and method for performing data transfers in
an intelligent electronic device’ relates to intelligent electronic devices (IEDs) and, in
particular, to a system and method for sending/receiving data to/from intelligent
electronic devices (IEDs) at high speeds over a network.
[007] US8532944B2 titled ‘Intelligent electronic device configuration verification’
relates to the field of Substation Automation systems with a standardized
configuration representation. More particularly, it relates to a method of verifying the
configuration of a first Intelligent Electronic Device in the SA system.

[008] EP2264967B1 titled ‘Inter-bay substation automation application’ is concerned
with an interface description or structure of an inter-bay Substation Automation (SA)
application. IEC 61850 SCD file is used to generate a formal description of the
interfaces of the inter-bay SA application.
[009] US8327049B2 titled ‘Electrical process interface device’ is concerned with an
electrical process interface device for provision in a low control and protection level
of a Substation Automation or Distribution Automation system; the device includes a
process interface unit for interfacing the electrical process at the low control and
protection level, which unit has a number of parallel data connections on which I/O
data related to control and protective devices on higher control and protection levels
may be transmitted. The device also includes a signal conversion unit connected to the
data connections, which unit packets data of the data connections according to a
communication standard used by control and protective devices on the at least one
higher control and protection level for allowing data to be directly transmitted between
the electrical interface device on the low control and protection level and other devices
on higher control and protection levels.
[010] US9478973B2 titled ‘Method for transfer of control between devices in a
substation system and a device thereof’ relates to the method and system for
coordinated transfer of control in a substation system having IED or logical
devices/servers using GOOSE messages with preconfigured data models with logical
nodes containing one or more data objects including private data objects (DO)
connected in the substation communication network.

[011] To overcome the problem of decentralized bay architecture, therefore, there
has been a need for a system and/ or a method for providing a centralized
architecture wherein the Processor module acts as an interface for data exchange
between the data acquisition cards and field communication.
OBJECTS OF THE INVENTION
[012] The main object of the present invention is to develop interfacing of the data
acquisition cards with the Processor module and their arrangement in the enclosure,
wherein the Processor module acts as an interface for data exchange between the
data acquisition cards and field communication.
[013] Another object of the present invention is to convey the information regarding
the techniques involved in the implementation of the information exchange between
two elements in the substation automation systems employing the IEC 61850
protocol.
[014] Further object of the invention is to enable the implementation with the
facility of appending the existence of a communication either between two IEDs at
the bay level or between bay and process level.
[015] Further object of the present invention is to develop application code in Real
Time Operating System (RTOS) environment and running on x86 hardware to
provide hard real time-stamp and better accuracies.

SUMMARY OF THE INVENTION
[016] The present invention is directed towards development of Auxiliary Bay
Control Unit having one microprocessor and number of data acquisition modules.
As all data processing is done by single processor, there are no data losses and at
the same time accuracies are increased.
[017] In an aspect, in the present invention the Auxiliary BCU obtains the data from
the sensors and after isolation and suitable amplification sends it to processor
module for computation. In addition to acquiring hardwired data, Auxiliary BCU
can be configured to acquire instantaneous data from the Availability based tariff
(ABT) meters over MODBUS protocol through its communication module. The
computed value is then mapped to IEC 61850 substation automation protocols for
communication with IEC 61850 compliant SCADA as well as local GUI (Graphic
User Interface) for local supervision or controlling of substation devices. The
moving window based averaging techniques provides better metering accuracies.
[018] In an aspect, the disclosed system consists of sensors for monitoring and
control of auxiliary systems available in control room like Float Cum Boost Charger
(FCBC charger) (220VDC), HMI UPS, Firefighting systems, (AC Distribution
board) ACDB and (DC Distribution board) DCDB power supply feeders, air
conditioning system. The data captured from low-end sensors is sent by the
Auxiliary BCU to SCADA over IEC 61850 communication protocol. All the data
acquisition modules are housed in an Electromagnetic Interference/
Electromagnetic Compatibility (EMI/EMC) compliant rack. Each of the data

acquisition modules perform a designated I/O function like analog input, digital
input, digital output. A common power supply is used to power all the modules.
The modules are generic and can be used interchangeably. This provides modularity
and ease of maintenance.
[019] In the present disclosure the functionality of input and output module is fixed.
The analog input module will acquire the data and send it to processor module for
further communication. Similarly digital input module will acquire the digital field
data and sent it to Processor module for further communication. Analog input,
Digital input and Digital output modules can be configured from the configuration
tool. The fixed functionality modules are advantageous from the point of view of
fault diagnosis and easy maintenance.
[020] The Auxiliary Bay Control Unit includes a single board computer, a
communication module and number of data acquisition modules for acquiring
analog and digital data. Each data acquisition module contains number of I/O
channels. The field connectors on the data acquisition card, acquire field data and
transfer data to Processor module via FRC (Flat Ribbon Cable) Connector. The
power supply is fed separately through power cable to all the data acquisition
modules and the Processor module. The separation of power cable and data cable
provides less interference to the data signals and improve the reliability.
[021] In an aspect, there is one Auxiliary BCU unit with one power supply. The
measurement, control, alarm monitoring and records is performed by one unit only.

As one unit is handling all the functions there is no data transfer delays, in addition
to better accuracies and no dependencies.
[022] In an aspect, the present invention is concerned with implementing the more
recent version of IEC 61850 which is known as edition 2 to take advantage of its
additional features. This helps in handling the information exchange between two
elements of the substation automation system.
[023] In an aspect, the present invention has the advantage of clearly understanding
the technique of tracking the communication by the IEC 61850 compliant client
between the elements of systems in a very explicit manner. This communication
could be between the control room and the IED, or between two IEDs, or between
process level IED and bay level IED. A standard real time operating system (RTOS)
running on x86 hardware platform has been used for implementing the Auxiliary
BCU. The implementation used the standard IEC 61850 APIs to interact with the
network and to respond to Client requests.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[024] It is to be noted, however, that the appended drawings illustrate only typical
embodiments of the present subject matter and are therefore not to be considered
for limiting of its scope, for the invention may admit to other equally effective
embodiments. The detailed description is described with reference to the
accompanying figures. In the figures, a reference number identifies the figure in
which the reference number first appears. The same numbers are used throughout
the figures to reference like features and components. Some embodiments of system

or methods or structure in accordance with embodiments of the present subject
matter are now described, by way of example, and with reference to the
accompanying figures, in which:
[025]Figure 1 illustrates the General card arrangement of the cards in the cabinet,
in accordance with an exemplary embodiment of the present disclosure.
[026] Figure 2 illustrates the front view of the rack with front door not mounted, in
accordance with an exemplary embodiment of the present disclosure.
[027] Figure 3 illustrates the General architecture of the Auxiliary BCU along with
the field I/Os and SCADA, in accordance with an exemplary embodiment of the
present disclosure.
[028] Figure 4 illustrates the block diagram of Modbus Meter interfacing with
IEC61850 SCADA, in accordance with an exemplary embodiment of the present
disclosure.
[029] Figure 5 illustrates the block diagram of the initialization routine describing
the basic flow of initialization sequences of IEC 61850 server driver, in accordance
with an exemplary embodiment of the present disclosure.
[030] Figure 6 illustrates the block diagram of the IEC 61850 server routine
describing the basic operation of IEC 61850 server functionality, in accordance
with an exemplary embodiment of the present disclosure.

[031] Figure 7 illustrates the block diagram of the GOOSE Publisher describing
IEC 61850 GOOSE Publisher functionality, in accordance with an exemplary
embodiment of the present disclosure.
[032] Figure 8 illustrates the block diagram of the GOOSE Subscriber describing
IEC 61850 GOOSE Subscriber functionality, in accordance with an exemplary
embodiment of the present disclosure.
[033] Figure 9 illustrates the block diagram of the Tracking services having the
tracking details updated by the respective modules with changing the configuration
or runtime values, in accordance with an exemplary embodiment of the present
disclosure.
[034] The figures depict embodiments of the present subject matter for the purposes
of illustration only. A person skilled in the art will easily recognize from the
following description that alternative embodiments of the structures and methods
illustrated herein may be employed without departing from the principles of the
disclosure described herein.
DETAIL DESCRIPTION OF THE PRESENT INVENTION WITH
REFERENCE TO THE ACCOMPANYING DRAWINGS OF PREFERRED
EMBODIMENTS
[035] While the embodiments of the disclosure are subject to various modifications
and alternative forms, specific embodiment thereof has been shown by way of
example in the figures and will be described below. It should be understood,

however, that it is not intended to limit the disclosure to the particular forms
disclosed, but on the contrary, the disclosure is to cover all modifications,
equivalents, and alternative falling within the scope of the disclosure.
[036] The terms “comprises”, “comprising”, or any other variations thereof used in
the disclosure, are intended to cover a non-exclusive inclusion, such that a device,
system, assembly that comprises a list of components does not include only those
components but may include other components not expressly listed or inherent to
such system, or assembly, or device. In other words, one or more elements in a
system or device proceeded by “comprises… a” does not, without more constraints,
preclude the existence of other elements or additional elements in the system or
device.
[037] In the preferred embodiment as illustrated in Figure 1 and Figure 2, the
Auxiliary BCU (100) designed around an Electromagnetic Interference/
Electromagnetic Compatibility (EMI/EMC) compliant 19 inch enclosure is
powered by a universal input power supply (106). The various electronic modules
are present to carry out functions like analog or digital data acquisition, signal
conditioning, field device actuation etc. All these functions are controlled and
coordinated by a central processor module (101), which is a Single Board Computer
(SBC). The following are the inputs from the field, which are subjected to the
required signal conditioning before digitizing:

• 4-20 mA sensor signals.
• Status signal from the switchgear in the form of binary data.
• Control signal to the switchgear in the form of binary data.
[038] In the preferred embodiment the electronic modules placement and their
interconnection is shown in the Figure 1 and general architecture of Auxiliary BCU
along with field I/Os and SCADA is shown in Figure 3. All the modules are
powered by 24V DC, which is derived from a universal input power supply (106).
The Auxiliary BCU (100) uses x86 based Processor module (101) which processes
various hardwired inputs or outputs and communicate the same from or to the upper
SCADA (109). Interconnection and data transfer between the two modules is via
Flat Ribbon Cable (FRC). Field connectivity is provided from the rear side of the
rack. . The present invention discloses a centralized architecture wherein the
processor module (101) acts as an interface for data exchange between the data
acquisition cards and field communication.
[039] In an exemplary embodiment, the various modules and their functionalities
are described herein. The analog inputs are in the form of 4-20mA signals. These
signals are suitably isolated and amplified by the 4-20mA Analog input module
(104) and then fed to the SBC Processor module (101).
[040] A plurality of Digital Input (DI) modules (102) provide isolation and level
translation to the status inputs signal to 5V level. Each DI module has a provision
for reading 220V DC status inputs. Status inputs from 4 digital modules (102) are
routed to a pair of 50-pin connectors (110) of the ADD-ON board (108) connected
to processor module (101) (referring Figure 2).

[041] In an exemplary embodiment, the processor module (101) is coupled with a
Communication module (105) which is having a plurality of RS232, a pair of
RS485 and LAN ports for communicating with the low end Energy meters and High
End SCADA (109). Front panel LEDs are provided for displaying the status of
alarm and trip. A local GUI (Graphic User Interface) (107) is provided for local
supervision or controlling of a substation device. The mapped data from said
SCADA (109) or the GUI (107) are fed to the communication module which
transmits the data to the central processor module (101). Digital outputs from the
Processor module (101) are routed to the digital output/ relay module (103) via base
board. Each relay module (103) caters to 16 digital outputs.
[042] In an exemplary embodiment, application code is developed in C language
in Real Time Operating System (RTOS) environment. Real-time Operating system
provides greater timings accuracy. The application is designed as multiple
processes with multiple threads. Each thread is designed to perform a particular
task. Algorithms have been developed for Analog and Digital Data acquisition,
Measurement, Sequence of Events (SOE) recording, Alarms recording and Data
transfer over IEC 61850 substation protocol.
[043] Figure 4 shows the block diagram of MODBUS Meter interfacing with
IEC61850 SCADA. The auxiliary BCU (100) obtains the metering data from the
lower-end devices like Multifunctional meters (MFM) or Multi-Functional
Transducers (MFT) over LAN/Serial link. It then maps the data to the upper-layer
SCADA over LAN media. The block diagram of the initialization routine

describing the basic flow of initialization sequences of IEC 61850 server driver is
shown in Figure 5.
Initialization Module
[044] Referring to the Figure 5, the main configuration file is the SCD file (302).
The Auxiliary BCU IEC Map file (303) is the configuration file concerned with
IED (Intelligent Electronic Device) application and IEC 61850 application put in a
configuration text file consisting of shared memory type (IN & OUT data types),
shared memory index for each of the IEC 61850 data in the IED Section of the SCD
file (302). IEC 61850 application internally loads the configuration file (303) at
start-up and reads and writes shared memory data according to the configuration. A
StartUp.cfg file (301) is provided to the IED User to facilitate the parsing of SCD
file (302) using SCL parser (305) compliant with IEC 61850 Edition 2.0 SCL
schema for this user’s IED. The configuration INI file will have IEC61850 Server
leaf name and corresponding mapped shared memory address and its type. File
encoder (306) is used for reading all the entries in the INI file, separated with TAB.
[045] SCL parser (305) will create MapInfo structure for linking the application
layer and 61850 library layer. This structure will have SCL Data type information
(307) with all leaf elements details (including leaf name, Logical Device, Data
Types etc.) for reading data from 61850 library layer and writing data to 61850
library layer and user application Layer.
[046] In an exemplary embodiment, the IED Data Mapping module (308) is using
the configuration file (303) provided by the IED User to identify the mapping

information related to the IED and IEC 61850 data objects. This module (308) fills
the IEC 61850 server index and shared memory address and type information to the
respective IEC 61850 data structures (313). At runtime, this information is used by
(308) module to feed data from the IED shared memory to IEC 61850 server.
[047] In an exemplary embodiment, the dynamic object creator takes the IEC 61850
- MMS configuration file as an input to initialize the MMS connections as well as
the MMS objects (304). The (304) module also configures the logging and
initializes the memory subsystem. The SCL file gets parsed further to decode the
type information details. The Logical device instance(s) (309) are created along
with the Logical node instances (310). The control blocks (311) such as buffered
report control blocks, un-buffered report control blocks, setting group control
blocks, SV (Sampled Value) and GOOSE control blocks, service tracking (314) are
initialized further by supervisory LN objects (315). After creating the base objects,
the corresponding functions are attached to each of the leaf variables in the form of
leaf functions (312). This information is used at run-time for read/write operations.
The initialization of IEC 61850 server structures helps in the entire implementation
module for easy and fast access of IEC 61850 and IED data at runtime.
[048] In an exemplary embodiment, the entire implementation of IEC 61850 is
divided into the following subsystems:
(I) IEC 61850 Server
[049] In an exemplary embodiment, this module provides all IEC 61850
communication as well as data model of IED for external IEC 61850 Clients. When
client requests for any of the IEC 61850 services, this module facilitates all the

validation and provides accession of data through IEC 61850 data models
configured via SCL XML (SCD) file (302). All IEC 61850 client requests are
addressed via pre-registered leaf functions (312). Module passes the logical control
to IED interface module whenever it needs access to IED data. This is the first
threaded module of IEC 61850 Server Implementation.
[050] With reference to Figure 6 it is understood that the IEC 61850 Server Module
handles all the IEC 61850 operations. This includes servicing client requests (401)
with client specific responses (408), validation of client requests (401) and passing
read write indications (402, 403) to internal data structures (404, 405). The other
important functionality of this module is to handle control blocks (406) according
to client specified parameters. This includes handling of Buffered and un-buffered
report control blocks, setting group control blocks and log control blocks. Providing
data information into this module is done by the data structures (404,405). Hence
these structures (404,405) are referred dynamically by IEC 61850 server module
for any transactions with external Clients. There are specific functions for handling
report data and log data (407). Log file recycling of entire system, limiting of
maximum size and acting as a circular file are managed by this module (407). This
functionality helps entire system to not use disk capacity in an unlimited manner.
(II) IEC GOOSE (Generic Object Oriented Substation Event) Publisher
[051] In an exemplary embodiment, this module facilitates the publishing of multi-
cast GOOSE packets to MAC addresses according to SCL definitions. Hence it
provides GOOSE data to external IEC GOOSE subscribers via IEC GOOSE

communication. Whenever there is any change in GOOSE data from IED, this
module facilitates all the validation and provides publication of data through IEC
GOOSE publisher control blocks configured via SCL XML (SCD) file (302). This
module uses the shared memory data copy to identify the changes in GOOSE data.
This is the second threaded module of IEC 61850 Server Implementation.
[052] With reference to Figure 7 it is understood that the IEC GOOSE Publisher
Module (GOCB Handler) (501) handles all the GOOSE data publishing operations
and Enable/Disable of GOOSE control blocks by any external Clients. The said
module (501) detects the discrete data changes (503) in GOOSE dataset variables
form DIGITAL-IN shared memory (502) and trigger new GOOSE publishing (504)
for that specific GOOSE control block. Re-transmission (505) of the triggered
GOOSE packets is handled by a separate function which take care of fast and slow
publishing of GOOSE packets into subnet interface (506).
[053] GOOSE module demands more performance than IEC 61850 server in terms
of its functionality of putting packets to Ethernet interface bypassing many
intermediate MMS layers. This makes GOOSE a connection less protocol, which
in turn demands re transmissions. This ensures the receiving of GOOSE packets at
the other end even if there is any packet loss. Subscribers interested in Auxiliary
BCU's GOOSE packets will be receiving the same in an efficient manner because
of this re transmission mechanism of IEC GOOSE module.
[054] A fixed number of GOOSE Control blocks is dedicated for GOOSE
Publishing. User can assign any dataset to these GOOSE control blocks while

creating ICD / CID files. User can also create new dynamic datasets for these
Publisher GOOSE control blocks.
(III) IEC GOOSE (Generic Object Oriented Substation Event) Subscriber
[055] In an exemplary embodiment, this module facilitates the subscribing of
multicast GOOSE packets from MAC addresses according to the External Reference
in SCL definitions. Hence it provides GOOSE data from external IEC GOOSE
publishers to the defined IED. Whenever there is any changed GOOSE data from the
subscriber module, it informs the IED via the shared memory. This is the third
threaded module of IEC 61850 Server Implementation.
[056] With reference to Figure 8, it is shown that the IEC GOOSE Subscriber
Module (GOCB Handler) (601) handles all the GOOSE data receiving operations
and Enable/Disable of GOOSE control blocks by any external Client. The module
(601) detects the data changes (603) in GOOSE dataset variables received and
updates the same to pre-configured shared memory blocks (604). This module (601)
also simultaneously updates the status in the GOOSE supervision logical node
module (605) for any client to monitor the status. The subnet interface module (606)
is registered to receive GOOSE packets only for the required MAC addresses. Filter
GOOSE packet function (602) ensures that it’s a goose packet and then finds the
corresponding goose subscription handle for it. The GOOSE Subscriber module
(601) demands more performance than IEC 61850 server in terms of its
functionality of receiving packets from Ethernet interface by avoiding many
intermediate MMS layers.

[057] The Configuration of Subscriber GOOSE Control Blocks are handled in the
following manner:
[058] External inputs section in the SCD File (302) provides information of remote
data attributes that may come from remote Publishers.
[059] During the creation of an SCD file (302), the SCL user should know about
the details of all remote GOOSE control blocks and their respective datasets, to
which the IED is going to subscribe.
[060] As per Edition 2 of IEC 61850, the remote IED details should be present in
the SCD file (302). The dataset elements in the subscribed GOOSE datasets are
mapped to digital output values of the shared memory using Aux BCU - IEC 61850
map file (302).
Service Tracking:
[061] In an exemplary embodiment, the technique of implementing the service-
tracking facility as per the Edition 2 of IEC 61850 is developed which is employed
to allow client to track the services in a communication.
[062] With reference to Figure 9, the tracking details are updated by the respective
modules Report service (URCB, BRCB) (801), GOCB service (802), Control (SPC,
DPC service) (803) or Setting group (SGCB) service (804) when changing
configuration or runtime values. These values are sent to the client (408), whenever
the client requests (401) for an indication from the server side.
[063] The following tracking services are implemented as per the IEC 61850
Edition 2 standard.

[064] (a) Continuously monitors the current BRCB (Buffered Report control
Block) values of module (801) and the old BRCB values and updates the data to
BRCB tracking node of module (805).
[065] (b) monitors the current URCB (Un-Buffered Report Control Block) values
of module (801) and the old URCB values and updates the data to URCB tracking
node of module (805).
[066] (c) Continuously monitors the current GOCB (GOOSE Control Block) values
of module (802) and the old GOCB values and updates the data to GOCB tracking
node of module (805).
[067] (d) Tracks the select operation in the module (803) and updates the data
according to the single point or Double point control of module (805).
[068] (e) Tracks the cancel operation in the module (803) and updates the data to
according to the single point or Double point control cancellation of module (805).
[069] (f) Tracks the select with value and open operation in the module (803) and
updates the data according to the single point or Double point control of module
(805).
[070] (g) Tracks the SGCB (Setting Group Control Block) parameters in the module
(804) and updates the data to SGCB tracking node of module (805).
[071] It should be noted that the description and figures merely illustrate the
principles of the present subject matter. It should be appreciated by those skilled in
the art that conception and specific embodiment disclosed may be readily utilized
as a basis for modifying or designing other structures for carrying out the same
purposes of the present subject matter. It should also be appreciated by those skilled

in the art that by devising various arrangements that, although not explicitly
described or shown herein, embody the principles of the present subject matter.
Furthermore, all examples recited herein are principally intended expressly to be
for pedagogical purposes to aid the reader in understanding the principles of the
present subject matter and the concepts contributed by the inventor(s) to furthering
the art and are to be construed as being without limitation to such specifically
recited examples and conditions. The novel features which are believed to be
characteristic of the present subject matter, both as to its organization and method
of operation, together with further objects and advantages will be better understood
from the following description when considered in connection with the
accompanying figures.
[072] These and other advantages of the present subject matter would be described
in greater detail with reference to the following figures. It should be noted that the
description merely illustrates the principles of the present subject matter. It will thus
be appreciated that those skilled in the art will be able to devise various
arrangements that, although not explicitly described herein, embody the principles
of the present subject matter and are included within its scope. The present
invention will now be described more specifically with reference to the following
specification.
[073] It should be noted that the description and figures merely illustrate the
principles of the present subject matter. It should be appreciated by those skilled in
the art that conception and specific embodiment disclosed may be readily utilized
as a basis for modifying or designing other structures for carrying out the same

purposes of the present subject matter. It should also be appreciated by those skilled
in the art that by devising various arrangements that, although not explicitly
described or shown herein, embody the principles of the present subject matter and
are included within its spirit and scope. Furthermore, all examples recited herein
are principally intended expressly to be for pedagogical purposes to aid the reader
in understanding the principles of the present subject matter and the concepts
contributed by the inventor(s) to furthering the art and are to be construed as being
without limitation to such specifically recited examples and conditions. The novel
features which are believed to be characteristic of the present subject matter, both
as to its organization and method of operation, together with further objects and
advantages will be better understood from the following description when
considered in connection with the accompanying figures.
[074] It will be understood by those within the art that, in general, terms used
herein, and especially in the appended claims (e.g., bodies of the appended claims)
are generally intended as “open” terms (e.g., the term “including” should be
interpreted as “including but not limited to,” the term “having” should be
interpreted as “having at least,” the term “includes” should be interpreted as
“includes but is not limited to,” etc.). It will be further understood by those within
the art that if a specific number of an introduced claim recitation is intended, such
an intent will be explicitly recited in the claim, and in the absence of such recitation
no such intent is present. For example, as an aid to understanding, the following
appended claims may contain usage of the introductory phrases “at least one” and
“one or more” to introduce claim recitations. However, the use of such phrases

should not be construed to imply that the introduction of a claim recitation by the
indefinite articles “a” or “an” limits any particular claim containing such introduced
claim recitation to inventions containing only one such recitation, even when the
same claim includes the introductory phrases “one or more” or “at least one” and
indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be
interpreted to mean “at least one” or “one or more”); the same holds true for the use
of definite articles used to introduce claim recitations. In addition, even if a specific
number of an introduced claim recitation is explicitly recited, those skilled in the
art will recognize that such recitation should typically be interpreted to mean at least
the recited number (e.g., the bare recitation of “two recitations,” without other
modifiers, typically means at least two recitations, or two or more recitations).
Furthermore, in those instances where a convention analogous to “at least one of A,
B, and C, etc.” is used, in general such a construction is intended in the sense one
having skill in the art would understand the convention (e.g., “a system having at
least one of A, B, and C” would include but not be limited to systems that have A
alone, B alone, C alone, A and B together, A and C together, B and C together,
and/or A, B, and C together, etc.). In those instances where a convention analogous
to “at least one of A, B, or C, etc.” is used, in general such a construction is intended
in the sense one having skill in the art would understand the convention (e.g., “a
system having at least one of A, B, or C” would include but not be limited to
systems that have A alone, B alone, C alone, A and B together, A and C together,
B and C together, and/or A, B, and C together, etc.). It will be further understood
by those within the art that virtually any disjunctive word and/or phrase presenting

two or more alternative terms, whether in the description, claims, or drawings,
should be understood to contemplate the possibilities of including one of the terms,
either of the terms, or both terms. For example, the phrase “A or B” will be
understood to include the possibilities of “A” or “B” or “A and B.”
[075] It will be further appreciated that functions or structures of a plurality of
components or steps may be combined into a single component or step, or the
functions or structures of one-step or component may be split among plural steps
or components. The present invention contemplates all of these combinations.
Unless stated otherwise, dimensions and geometries of the various structures
depicted herein are not intended to be restrictive of the invention, and other
dimensions or geometries are possible. In addition, while a feature of the present
invention may have been described in the context of only one of the illustrated
embodiments, such feature may be combined with one or more other features of
other embodiments, for any given application. It will also be appreciated from the
above that the fabrication of the unique structures herein and the operation thereof
also constitute methods in accordance with the present invention. The present
invention also encompasses intermediate and end products resulting from the
practice of the methods herein. The use of “comprising” or “including” also
contemplates embodiments that “consist essentially of” or “consist of” the recited
feature.
[076] Although embodiments for the present subject matter have been described in
language specific to structural features, it is to be understood that the present subject
matter is not necessarily limited to the specific features described. Rather, the

specific features and methods are disclosed as embodiments for the present subject
matter. Numerous modifications and adaptations of the system/component of the
present invention will be apparent to those skilled in the art, and thus it is intended
by the appended claims to cover all such modifications and adaptations which fall
within the scope of the present subject matter.
[077] The various operations of methods described above may be performed by any
suitable means capable of performing the corresponding functions. The means may
include various hardware component(s) and/or module(s), including, but not limited
to a circuit, an application specific integrated circuit (ASIC), or processor.
Generally, where there are operations illustrated in figures, those operations may
have corresponding counterpart means-plus-function components with similar
numbering.
[078] The various illustrative logical blocks, modules, units and circuits described
in connection with the present disclosure may be implemented or performed with a
general purpose processor, a digital signal processor (DSP), an application specific
integrated circuit (ASIC), a field programmable gate array (FPGA) or other
programmable logic device (PLD), discrete gate or transistor logic, discrete
hardware components, or any combination thereof designed to perform the
functions described herein. A general- purpose processor may be a microprocessor,
but in the alternative, the processor may be any commercially available processor,
controller, microcontroller, or state machine. A hardware processor may also be
implemented as a combination of computing devices, e.g., a combination of a DSP
and a microprocessor, a plurality of microprocessors, one or more microprocessors

in conjunction with a DSP core, or any other such configuration. If implemented in
hardware, an example hardware configuration may comprise a processing system
in a physical or wireless node. Hardware units store technical instructions, data or
any combination thereof that, when executed by an apparatus such as a processor
which alone or in combination with other hardware components, cause the
processing system to perform various technical functions.
ADVANTAGES OF THE INVENTION
[079] The advantage of the present invention is that it develops interfacing of the
data acquisition cards with the Processor module with the Processor module acting
as an interface for data exchange between the data acquisition cards and field
communication.
[080] Another advantage of the present invention is that it engages the
implementation of the information exchange between two elements in the
substation automation systems employing the IEC 61850 protocol.
[081] Further advantage of the invention is that it enables the implementation with
the facility of appending the existence of a communication either between two IEDs
at the bay level or between bay and process level.
[082] Further advantage of the present invention is that it develops application code
in Real Time Operating System (RTOS) environment running on X86 hardware to
provide hard real time-stamp and better accuracies.

We Claim:
1. A substation automation system for implementing an International
Electrotechnical Commission (EC) 61850 server communication protocol,
comprising:
an auxiliary Bay Control Unit (BCU) (100), wherein the BCU (100)
comprises:
a plurality of data acquisition modules (102-104) housed in a single
Electromagnetic Interference/ Electromagnetic Compatibility (EMI/EMC)
compliant rack for performing a designated analog input, digital input and
digital output functions, and
a central processor module (101) communicatively coupled with the
plurality of data acquisition modules (102-104) and a communication
module (105) for exchanging data therebetween via a Flat Ribbon Cable
(FRC);
a Graphic User Interface (GUI) (107) communicatively connected with
the communication module (105) for local supervision or controlling of a
substation device;
an input power supply unit (106) for providing power to said modules
(101-105, 107) via a power cable; and
at least one IEC 61850 compliant Supervisory Control and Data
Acquisition (SCADA) (109) operatively connected with said BCU (100) at

the communication module (105), wherein the communication module
(105) communicates an information from the processor module (101) to the
IEC 61850 compliant SCADA (109) and the GUI (107) and receives a
mapped data therefrom.
2. The system as claimed in claim 1, wherein the BCU (100) facilitates a
centralized bay architecture by interfacing the data acquisition module (102-
104) and communication module (105) by single processor module (101).
3. The system as claimed in claim 1, wherein the plurality of data acquisition
modules (102-104) performing designated input or output functions comprises
one or more digital input module (102), one or more analog input module (104)
and one or more digital output module (103), wherein the one or more digital
input (102) and/or the analog input (104) module acquires a data from one or
more binary signals and sends it to the processor module (101) for further
communication, wherein the one or more digital output module (103) receives
a digital outputs from the Processor module (101).
4. The system as claimed in claim 1, wherein the processor module (101)
processes the one or more 4-20mA analog input signals from the analog input
module (104) with amplification.
5. The system as claimed in claim 1, wherein the processor module (101)
processes the one or more status signal from a switchgear and the one or more
control signal to the switchgear in the form of binary data.

6. A method of implementing an International Electrotechnical Commission (IEC)
61850 server communication protocol in a substation automation system, said
method comprising:
initializing an auxiliary Bay Control Unit (BCU) (100) as an
International Electrotechnical Commission (IEC) 61850 server by using
information provided by an Intelligent Electronic Device (IED) user for
identifying the mapping information related to the IED and the IEC 61850 data
object;
monitoring a plurality of input data from one or more digital input (102)
and/or one or more analog input (104) module with a transmission of the same
to a central processor module (101) of the BCU (100);
transmitting the processed input data from said central processor module
(101) to a communication module (105) communicatively coupled with said
central processor module (101);
communicating the processed input data to a Supervisory Control and
Data Acquisition (SCADA) (109) and a Graphic User Interface (GUI) (107) via
the communication module (105) over an IEC 61850 communication protocol
mapped to a switchgear device for operation;
forwarding a mapped data from the SCADA (109) or the Local GUI
(107) to said central processor module (101) via the communication module
(105) using said IEC 61850 communication protocol; and
receiving an output data at one or more digital output module (103) from
the central processor module (101) for real time operation.

7. The method as claimed in claim 6, wherein the IEC 61850 server
communication protocol generates a communication between a control room
and an Intelligent Electronic Device (IED) or between the two IEDs or between
the process level IED and the bay level IED.