General - Siemens 6MD85 Manual

Introduction

1.1 General

1.1 General
The digital multifunctional protection and bay controllers of the SIPROTEC 5 device series are equipped with a
powerful microprocessor. As a result, all tasks, from acquiring measurands to entering commands in the
circuit breaker, are processed digitally.
Analog Inputs
The measuring inputs transform the currents and voltages sent by the instrument transformers and adapt
them to the internal processing level of the device. A SIPROTEC 5 device has a current transformer and,
depending on the device type, a voltage transformer. The current inputs are therefore intended for the detec-
tion of phase currents and ground current. The ground current can be detected sensitively using a core
balance current transformer. In addition, phase currents can be detected very sensitively for a particularly
precise measurement. The voltage inputs detect the measuring voltage of device functions requiring current
and voltage measured values.
The analog values are digitized in the internal microcomputer for data processing.
Microcomputer System
All device functions are processed in the microcomputer system.
This includes, for example:
•
Filtering and preparation of the measurands
•
Constant monitoring of the measurands
•
Monitoring of the pickup conditions for the individual protection functions
•
Querying of limiting values and time-outs
•
Controlling of signals for the logic functions
•
Decision about the trip and close commands
•
Storage of indications, fault data, and fault values for fault analysis
•
Administration of the operating system and its functions, such as data storage, real-time clock, communi-
cation, interfaces, etc.
•
External distribution of information
Binary Inputs and Outputs
Using the binary inputs and outputs, the device receives information from the system or from other devices
(such as locking commands). The most important outputs include the commands to the switching devices and
the indications for remote signaling of important events and states.
Front Elements
For devices with an integrated or offset operation panel, LEDs and an LC display on the front provide informa-
tion on the device function and report events, states, and measured values. In conjunction with the LC display,
the integrated keypad enables on-site operation of the device. All device information such as setting parame-
ters, operating and fault indications or measured values can be displayed, and setting parameters changed. In
addition, system equipment can be controlled via the user interface of the device.
Serial Interfaces
The serial interface in the front cover enables communication with a personal computer when using the DIGSI
operating program. As a result, the operation of all device functions is possible. Additional interfaces on the
back are used to realize various communication protocols.
32 SIPROTEC 5, High-Voltage Bay Controller, Manual
C53000-G5040-C015-9, Edition 11.2017