Alstom MiCOM P846, Technical Manual

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Firmware Design P846/EN FD/D
MiCOM P846
(FD) 9-3
FD
1. FIRMWARE DESIGN
1.1 Hardware overview
The relay hardware is based on a modular design whereby the relay is made up of an
assemblage of several modules that are drawn from a standard range. Some modules are
essential while others are optional depending on the user’s requirements.
The different modules that can be present in the relay are as follows:
1.1.1 Processor board
The processor board performs all calculations for the relay and controls the operation of all
other modules within the relay. The processor board also contains and controls the user
interfaces (LCD, LEDs, keypad, and communication interfaces).
1.1.2 Co-processor board
The co-processor board performs all the calculations necessary to process the algorithms
used in the open line detector function.
1.1.3 Input module
The input module converts the information contained in the analog and digital input signals
into a format suitable for processing by the processor board. The standard input module
consists of two boards; a transformer board to provide electrical isolation and a main input
board which provides analog to digital conversion and the isolated digital inputs.
1.1.4 Power supply module
The power supply module provides a power supply to all of the other modules in the relay, at
three different voltage levels. The power supply board also provides the EIA(RS)485
electrical connection for the rear communication port. On a second board the power supply
module contains the relays that provide the output contacts. The first four are fast static
contacts with a response to command < 1ms. The last four are standard contacts with
response < 5ms
The power supply module also provides a 48V external field supply output to drive the opto
isolated digital inputs (or the substation battery may be used to drive the optos).
1.1.5 IRIG-B board
This board, which is optional, can be used where an IRIG-B signal is available to provide an
accurate time reference for the relay. There is also an option on this board to specify a fiber
optic rear communication port, for use with Courier, MODBUS, DNP3.0 and IEC60870-5-103
communication.
1.1.6 Second rear comms. board
The optional second rear port is designed typically for dial-up modem access by protection
engineers/operators, when the main port is reserved for SCADA traffic. Communication is
via one of three physical links; K-Bus, EIA(RS)485 or EIA(RS)232. The port supports full
local or remote protection and control access by MiCOM S1 software. The second rear port
is also available with an on board IRIG-B input.
1.2 Software overview
The software for the relay can be conceptually split into four elements; the real-time
operating system, the system services software, the platform software and the protection
and control software. These four elements are not distinguishable to the user, and are all
processed by the same processor board. The distinction between the four parts of the
software is made purely for the purpose of explanation here: