ABB REF601 Feeder protection and control

ABB REF601 Feeder protection and control

Description

The REF601 is a dedicated feeder protection and control relay.  The REJ601 is an overcurrent protection relay without breaker  control. These relays are intended for the protection of utility  substations and industrial power systems within primary and  secondary distribution networks. They are members of ABB’s  Relion® product family and part of its 605 series.These relays, provide an optimized composition of protection,  monitoring and control functionality in one unit, with the best  performance usability in its class and are based on ABB’s indepth knowledge of protection and numerical technology.

Relay functions

The REF601 and REJ601 can be pre-configured which facilitates easy and fast commissioning of switchgear.  To emphasize the simplicity of using these relays, only application specific parameters need to be set within the relay’s intended area of application. The standard signal configuration can  be altered by LHMI (local human-machine interface). The relays are available in three alternative application configurations, as indicated in Table 2.  

Protection functions

The REF601 and REJ601 offer three-stage overcurrent and twostage ground-fault protection functions. The transformer inrush  detector function is incorporated to prevent unwanted tripping  due to energizing of transformers. The REF601 and REJ601 offer three-stage overcurrent and  two-stage ground fault protection functions. The low-set stages  for overcurrent and ground fault protection are equipped with  selectable characteristics – Definite Time (DT) and Inverse Definite Minimum Time (IDMT). The relays feature standard IDMT  characteristics according IEC 61255-3 - Normal Inverse, Very  Inverse, Extremely Inverse, Long-time Inverse. They also feature  characteristics according to ANSI C37.112 - Moderate Inverse,  Normal Inverse, Very Inverse, and Extremely Inverse. The relays  also have a special characteristic RI Inverse (RI) for better coordination with the rest of the network. Additionally the relays also  support two setting groups.The REF601 and REJ601 also offer thermal overload protection  for feeders, cables and transformers. Other protections include negative phase sequence protection, phase discontinuity  protection and circuit breaker failure protection. The relays also  have an auto-recloser option for overhead line feeders.

Application

The REF601 and REJ601 are protection relays aimed at protection and control of incoming and outgoing feeders in MV  distribution substations. They can be applied for short-circuit,  overcurrent and ground-fault protection of overhead lines and  cable feeders of distribution and sub-distribution networks. The inrush current stabilization function allows the relays to be  used as the main protection for distribution transformers.

The relay with application configuration B offers non-directional  overcurrent and ground-fault protection. The residual current for  the ground-fault protection is derived from the phase currents.  When applicable, core-balance current transformers can be  used for measuring the residual current, especially when sensitive ground-fault protection is required.

The application configuration C adds thermal overload protection for feeders, cables and transformers, phase discontinuity  protection and circuit breaker failure protection.

The application configuration D provides the highest functionality with incorporation of negative phase sequence protection and  a multi-shot auto-recloser function making the relay suitable for  overhead line feeders.

Inputs and outputs

All configurations are offered with conventional CTs and are  equipped with four 1A or 5A analog current inputs. Three are for  phase current and one for ground current measurement.

The relays all have four standard binary inputs. The binary inputs  can be configured for various functions like blocking, protection  reset, breaker position, breaker control and trip circuit supervision. These signals can be mapped to binary outputs and LEDs  for indications. Individual inputs can be configured either as  “Inverted” or “Non Inverted”.

The REF601 and REJ601 both have six output contacts. Of  these, two are power outputs and four are signaling outputs.  The output contacts can be configured for different functions  like routing of protection start/trip signals, external trip/open,  external close command, and trip circuit monitoring status, etc.  One dedicated output contact is available for normal condition/ IRF status indication.

All binary input and output contacts are preconfigured according to the default configuration. However, they can be easily  reconfigured by using the LHMI menu.

Application warning

In the case that the relay is supplied with UPS step-wave or  square-wave, an interposing transformer is needed to keep the  supply voltage (peak voltage) below the upper limit of the relay. These are the recommended transformer characteristics: 

− Nominal power: 20 VA  

− Secondary voltage: in the range 30...150 V AC