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. 

9. Recorded data The relays store fault records of analog values for the last five trip events in non-volatile memory. The fault recording is triggered by the trip signal of a protection function. Each fault record includes the current values for three phases and ground current along with a time stamp. These records enable the user to analyze the five most recent power system events. The relays record the number of phase and ground fault trip events into dedicated trip counters. These trip counters cannot be reset by the user and are stored in non-volatile memory. The recorded information can be accessed locally via the user interface on the relay front panel and can be uploaded for subsequent fault analysis. 

10. Self-supervision and test function The relay’s built-in self-supervision system continuously monitors the state of the relay hardware and the operation of the relay software. Any fault or malfunction detected will signal an alert for the operator. A permanent relay fault will block the protection functions of the relay to prevent incorrect relay operation. The relays support a built-in test mode which enables the user to test the relay HMI and binary outputs. 

11. Trip-circuit monitoring The trip-circuit monitoring continuously monitors the availability and operability of the trip circuit. It provides open-circuit monitoring both when the circuit breaker is in its closed and in its open position. It also detects loss of circuit-breaker control voltage. 

12. Access control To protect from unauthorized access and to maintain the integrity of information, the relays are armed with a three level, role-based user authentication system with individual passwords for operator, engineer and administrator levels. 

There are two alternative password protection options. 

The default is a combination of different navigation keys. 

The alternative is an alpha-numeric password. 

The user can select the password option based on their requirement.

13. Local HMI The local HMI features an alpha-numeric LCD display, LED indicators and navigation keys. Measurements, recorded data, events and settings can be viewed on the display. The relays have six LED indicators on the LHMI which are preconfigured for normal/IRF condition, pickup, trip, phase fault trip, ground fault trip and trip circuit fault indications. Support for multiple languages is built-in to the REF601 and REJ601. 

14. 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. 

15. Communication The relays are available with an optional communication feature with Modbus RTU protocol or IEC 60870-5-103 on RS-485 bus with two wire connection. This allows the relays to connect to a control and monitoring system through serial communication for remote monitoring. The communication card may be added at any time. 

16. 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