ABB Relion® Protection and Control REX640 Petersen Coil control page

Control

REX640 integrates functionality for controlling objects such as

circuit breakers, disconnectors, earthing switches, on-load tap

changers and Petersen coils via the LHMI or by means of

remote controls. The relay includes three circuit breaker control

blocks. In addition, the relay features 14 disconnector control

blocks intended for the motor-operated control of

disconnectors or a circuit breaker truck and three control

blocks intended for the motor-operated control of the earthing

switch. Furthermore, the relay includes eight additional

disconnector position indication blocks and three earthing

switch position indication blocks that can be used with

disconnectors and earthing switches that are only manually

controlled.

The touch screen LHMI supports a single-line diagram with

control points and position indication for the relevant primary

devices. Interlocking schemes required by the application are

configured using Signal Matrix or Application Configuration in

PCM600.

REX640 includes two autoreclosing functions, each with up to

five programmable autoreclosing shots of desired type and

duration. A load-shedding function performs load shedding

based on underfrequency and the rate of change of the

frequency.

To validate correct closing conditions for a circuit breaker,

REX640 contains a synchrocheck function. For installations

including synchronous generators, REX640 introduces a

synchronizer that actively controls the generator’s voltage and

frequency in order to reach a synchronous situation across the

circuit breaker. The synchronizer functionality is available for a

generator circuit breaker as well as for a non-generator

(network) circuit breaker. A complete installation-wide

synchronizing system can be built using the REX640 relays. The

maximum size of the synchronizing system is eight generator

breakers and 17 non-generator breakers.

Synchronization of a generator circuit breaker can be

implemented using a single REX640 relay including the

ASGCSYN function block. The relay interfaces the external

measurement and control circuitry via hardwired binary and

analog signals. The excitation and prime mover control signals

are based on pulse commands, either with fixed or variable

length. The synchronizer function block has three different

function modes: manual, semi-automatic and automatic. In

each of these modes, the LHMI acts as the local user interface.

The LHMI includes the necessary command, indication and

measurement features for each of the modes, thus rendering

the conventional dedicated synchronizing panel unnecessary.

REX640 also supports systems in which non-generator circuit

breakers are synchronized. The prerequisite is that all the

feeders within the system are equipped with REX640 relays.

The generator relays have to contain the ASGCSYN function

block and all the non-generator relays need to contain the

ASNSCSYN function block. In addition, all the REX640 relays

have to contain the coordinator function block ASCGAPC. The

role of ASCGAPC is to model the system primary circuit

connection state to involve the correct generators for the

synchronization of a non-generator breaker and to interact

between the ASGCSYN and ASNSCSYN function blocks. The

information exchange between ASCGAPC, ASGCSYN and

ASNSCSYN is carried out via binary and analog GOOSE

signalling as per IEC 61850-8-1. The LHMI dedicated to the

relay (breaker) works as the local user interface for a non

generator breaker synchronizing. The available synchronizing

modes are “automatic” and “semi-automatic”. A manual

synchronization of the non-generator breaker can be carried

out as a back-up solution in situations where the

communication system (IEC 61850-8-1) is not available. This

requires operator actions from two LHMIs, namely from the

LHMI of the concerned non-generator breaker and the LHMI of

the manually selected generator relay.