GE Multilin DTP-B, Instruction Manual

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8. HARDWARE DESCRIPTION
8-4 DTP-B Digital Transformer Protection GEK-106243E
8.1.6 PROTECTION CPU PROCESSING BOARD
This module is the main part of the equipment, as regards protection functions. Its main functions are:
•
Sampling of analog inputs coming from the magnetic module.
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Protection algorithms evaluation.
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Protection logic and auxiliary functions.
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Monitoring functions, events register, oscillography register, etc.
•
Self-check of the unit.
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Protection data communication to the communications CPU.
The core of the CPU module is a 16-bit micro-processor together with its auxiliary associated circuitry.
8.1.7 COMMUNICATIONS CPU MODULE
The core of the communications CPU is very similar to the Protection CPU’s, and it also consists of a 16-bit
microprocessor, together with the associated circuitry.
The main function performed by the Communications CPU module is maintaining and controlling the
communications in the following channels:
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Internal communication with the Protection CPU module.
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Local mode communication with a PC by the front communications port.
•
Remote mode communication by the rear communication port.
•
Man-machine interface, by means of keypads and displays (alphanumerical).
8.1.8 INPUTS/OUTPUTS MODULE.
DTP units have been designed to allow the maximum capacity for inputs and outputs in each board, maintaining
at the same time complete reliability against electromagnetic disturbance.
Every board input has a resistive attenuate, which adequates the external voltage battery levels (48 V, 125 V,...)
to the needs of the optocoupler that provides each input with galvanic isolation. As the majority of these inputs
come from elements connected to the substation equipment, together with the resistive attenuate one passive
filter is provided, in order to obtain a better behaviour against electromagnetic disturbance.
Each of the 8 outputs are heavy duty relays, with a continuous capacity of 16 Amperes, and a breaking capacity of
4000 VA.
Each of these relays has an only contact, which can be configured separately as normally open or normally
closed (N.O. + N.C.) by means of jumpers (fixed by welding) placed in the board.
In every configuration, these are non potential contacts, without common elements, and all of them have varistors
between their terminals in order to protect them against overvoltages generated by the coils to which they are
connected. This provides a high immunity against electrical interferences.