Alstom MiCOM P846, Technical Manual

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Firmware Design P846/EN FD/D
MiCOM P846
(FD) 9-5
FD
1.2.2 System services software
The system services software provides the low-level control of the relay hardware. For
example, the system services software controls the boot of the relay’s software from the
non-volatile flash EPROM memory at power-on, and provides driver software for the user
interface via the LCD and keypad, and via the serial communication ports. The system
services software provides an interface layer between the control of the relay’s hardware and
the rest of the relay software.
1.2.3 Platform software
The platform software deals with the management of the relay settings, the user interfaces
and logging of event, alarm, fault and maintenance records. All of the relay settings are
stored in a database within the relay that provides direct compatibility with Courier
communications. For all other interfaces (i.e. the front panel keypad and LCD interface,
Courier and DNP3.0) the platform software converts the information from the database into
the format required. The platform software notifies the protection & control software of all
settings changes and logs data as specified by the protection & control software.
1.2.4 Protection & control software
The protection and control software performs the calculations for all of the protection
algorithms of the relay. This includes digital signal processing such as Kalman filtering and
ancillary tasks such as the measurements. The protection & control software interfaces with
the platform software for settings changes and logging of records, and with the system
services software for acquisition of sample data and access to output relays and digital
opto-isolated inputs.
1.2.5 Disturbance recorder
The analog values and logic signals are routed from the protection and control software to
the disturbance recorder software. The platform software interfaces to the disturbance
recorder to allow extraction of the stored records.
1.3 Hardware modules
The relay is based on a modular hardware design where each module performs a separate
function within the relay operation. This section describes the functional operation of the
various hardware modules.
1.3.1 Processor board
The relay is based around a TMS320VC33 floating point, 32-bit digital signal processor
(DSP) operating at a clock frequency of 75MHz. This processor performs all of the
calculations for the relay, including the protection functions, control of the data
communication and user interfaces including the operation of the LCD, keypad and LEDs.
The processor board is located directly behind the relay’s front panel which allows the LCD,
function keys and LEDs to be mounted on the processor board along with the front panel
communication ports. These comprise the 9-pin D-connector for EIA(RS)232 serial
communications (e.g. using MiCOM S1 and Courier communications) and the 25-pin D-
connector relay test port for parallel communication. All serial communication is handled
using a field programmable gate array (FPGA).
The memory provided on the main processor board is split into two categories, volatile and
non-volatile; the volatile memory is fast access SRAM which is used for the storage and
execution of the processor software, and data storage as required during the processor’s
calculations. The non-volatile memory is sub-divided into 2 groups; 4MB of flash memory for
non-volatile storage of software code, present setting values, text, configuration data, latched
data signals (from control inputs, function keys, LEDs, relay outputs) and 2MB of battery
backed-up SRAM for the storage of disturbance, event, fault and maintenance record data.