ABB feeder protection and control REF601 and REJ601 ANSI

ABB feeder protection and control REF601 and REJ601 ANSI

1. 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 utilitysubstations and industrial power systems within primary andsecondary distribution networks. They are members of ABB’sRelion 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 bestperformance usability in its class and are based on ABB’s indepth knowledge of protection and numerical technology.

  2. 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.

3. Protection functions The REF601 and REJ601 offer three-stage overcurrent and twostage ground-fault protection functions. The transformer inrushdetector function is incorporated to prevent unwanted trippingdue to energizing of transformers.The REF601 and REJ601 offer three-stage overcurrent andtwo-stage ground fault protection functions. The low-set stagesfor overcurrent and ground fault protection are equipped withselectable characteristics – Definite Time (DT) and Inverse Definite Minimum Time (IDMT). The relays feature standard IDMTcharacteristics according IEC 61255-3 - Normal Inverse, VeryInverse, Extremely Inverse, Long-time Inverse. They also featurecharacteristics 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 alsosupport two setting groups. The REF601 and REJ601 also offer thermal overload protectionfor feeders, cables and transformers. Other protections include negative phase sequence protection, phase discontinuityprotection and circuit breaker failure protection. The relays alsohave an auto-recloser option for overhead line feeders.

4. 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. 

5. Optimized for limited space With their compact size and unique technical features, the REF601 and REJ601 are ideal for retrofits, compact switchgear and switchgear with limited space. These relays have a small mounting depth and do not have any loose mounting accessories. Uniquely, the REF601 and REJ601 use a press-fit mounting arrangement, suitable for quick and easy installation on switchgear 

6. Control The REF601 features control of one circuit breaker with dedicated push-buttons and guidance on local HMI for opening and closing. It includes two dedicated outputs for breaker control. The breaker control is also possible through optional MODBUS RTU or IEC 60870-5-103 communication. 

7. Measurement All versions of the relay continuously measure phase currents and ground current. Ground current can be measured using an external zero sequence current transformer or can be calculated internally. During operation, the default view of display shows the highest loaded phase current in primary terms (Amps) and the ground current. The values measured can be accessed locally via the user interface on the relay or remotely via the communication interface of the relay. These relays continuously measure negative sequence current, thermal level and counter values if these functions are supported as per application configurations

8. Event log To collect sequence of events (SoE) information, the relays incorporate non-volatile memory with a storage capacity of 100 events with associated time stamps and a resolution of 1 ms. The event log includes trip circuit monitoring status, protection operation status, binary I/O status and relay fault code. The event logs are stored sequentially, the most recent being first and so on. The non-volatile memory retains its data in the event of temporary auxiliary supply loss. The event log facilitates detailed post-fault analysis of feeder faults and disturbances. The SoE information can be accessed locally via the user interface on the relay front panel or remotely via the communication interface of the relay.