GE Multilin W650, Instruction Manual

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GEK-113032A W650 Wind Generator Protection System 7-1
7 IEC 61850 PROTOCOL 7.1 IEC61850 GENERIC SUBSTATION STATE EVENT (GSSE)
7
7 IEC 61850 PROTOCOL 7.1IEC61850 GENERIC SUBSTATION STATE EVENT (GSSE) 7.1.1 REMOTE DEVICES
7.1.1.1 REMOTE I/O OVERVIEW
Remote inputs and outputs, which are a means of exchanging information regarding the state of digital points between
remote devices, are provided in accordance with the IEC61850 Generic Substation State Event (GSSE) specifications.
The sharing of digital point state information between GSSE equipped relays is essentially an extension to PLC to allow
distributed PLC by making operands available to/from devices on a common communications network. In addition to digital
point states, GSSE messages identify the originator of the message and provide other information required by the
communication specification. All devices listen to network messages and capture data from only those messages that have
originated in selected devices.
GSSE messages are designed to be short, high priority and with a high level of reliability. The GSSE message structure
contains space for 128 bit pairs representing digital point state information. The IEC61850 specification provides 32 DNA
bit pairs, which are status bits representing pre-defined events. All remaining bit pairs are UserSt bit pairs, which are status
bits representing user-definable events. The W650 implementation provides 64 of the 96 available UserSt bit pairs.
The IEC61850 specification includes features that are used to cope with the loss of communication between transmitting
and receiving devices. Each transmitting device will send a GSSE message upon a successful power-up, when the state of
any included point changes, or after a specified interval (the “default update” time) if a change-of-state has not occurred.
The transmitting device also sends a “hold time” which is set to four point five times the programmed default time, which is
required by the receiving device.
Receiving devices are constantly monitoring the communications network for messages they require, as recognized by the
identification of the originating device carried in the message. Messages received from remote devices include the
message “hold time” for the device. The receiving relay sets a timer assigned to the originating device to the “hold time”
interval, and if it has not received another message from this device at time-out, the remote device is declared to be non-
communicating, so it will use the programmed default state for all points from that specific remote device. This mechanism
allows a receiving device to fail to detect a single transmission from a remote device which is sending messages at the
slowest possible rate, as set by its “default update” timer, without reverting to use of the programmed default states. If a
message is received from a remote device before the “hold time” expires, all points for that device are updated to the states
contained in the message and the hold timer is restarted. The status of a remote device can be displayed. The GSSE
facility provides for 32 remote inputs and 96 remote outputs.
7.1.1.2 LOCAL DEVICES ID OF DEVICE FOR TRANSMITTING GOOSE MESSAGES
The device ID that identifies the originator of the message is ONLY programmed in the EnerVista 650 Setup (see Figure 7–
1:)
Setpoint > Input/Outputs > Remote Comms > W650 ID