DTIVA2-EP

 EuroProt familija
DIGITAL OVERCURRENT PROTECTION AND AUTOMATIC RECLOSING DEVICE
 
The digital complex overcurrent protection and automatic reclosing device of type DTIVA2-EP is part of device family named EuroProt. This short description contains special data of this type. General and common features of EuroProt family can be found in the EuroProt system information sheet. Accordingly it is proposed to study both this short description and system information sheet too, in order to understand the device entirely.
 
DTIVA2-EP
 
Application field
 
The digital complex overcurrent protection of type DTIVA2-EP with independent time delaying and three shot reclosing device is applied on overhead lines of effectively not earthed (middle voltage) network where the selective detection of an earth fault is solved by the aid of a current rising resistor inserted to the network star point after an earth fault has occured, and where a phase fault causes overcurrent exceeding the rated current, hence it can selectively be catched by overcurrent relays, and where more shot reclosing device is also needed.
 
Main features
 
  • The protection part of device consists of:
    • three phase independent time delaying high setting overcurrent stage (I>>)
    • three phase independent time delaying low setting overcurrent stage (I>)
    • zero sequence independent time delaying high setting overcurrent stage (3Io>>)
    • zero sequence independent time delaying low setting overcurrent stage (3Io>)
    • self feeding overcurrent back up protection (if ordered)
  • The additional characteristics of protection part of the device:
    • with parametring, working of the two zero sequence overcurrent stages may be bound to the permission of a external zero sequence voltage relay (Uo>)
    • delayings may be independently set (high and low current stages as well as accelerated stages)
    • complition of the low current zero sequence overcurrent stage with zero sequence directional feature (3Io>So) may be requested as an option
  • The reclosing part of the device consists of:
    • one fast reclosig shot (FR)
    • two slow reclosing shot (1st and 2nd SR)
  • The additional characteristics of reclosing part of the device:
    • programmable to accelerated or selective trip after the first trip, after FR, after SR's and after the definite trip
    • each reclosing shot may be separately active or blocked
    • the automatic reclosing part may be separately programmed for phase and earth faults
  • The zero sequence current also starts the earth fault current increasing automatic device (FÁVA) blocking in the earth fault holding program of DTIVA2-EP, so it is not necessary to mount Uo> round circuit where it has not been realized
  • Two automatic working program-packs may be set on the device, to be able to realize easily the change of reclosing working mode by hand or by remote control
  • The device may be set to trip on existing Uo> when a work under voltage (Live Line Working, LLW) is made
  • Continuous and periodical monitoring system is built into the device including the check of the basic current circuits and the control circuits
  • The device has 14 output contacts (12 NO and 2 NC), from them six pcs has fixed connections, and connection of eight pcs may be programmed by digital software matrix
  • Event log for 50 events store and event sequence recorder for 300 events with 1 ms resolution is built in
  • The device may be synchronized by the Word Time Synchronizer (WTS) made by PROTECTA Co. Ltd.
  • The device is controlled by microprocessors excluded the back up protection, and may be handled by a menu system.
Working principle
 
Input currents of the device through inductive auxiliary C.T. and analogue low pass filter go to the multiplexer, and the S/H, where each phase current and the zero sequence current will be sampled by 0.5 ms, and each overcurrent stage is separately applied to each input currents.

The time delaying of the eight overcurrent relais may be independently set. The high and low setting stages and the accelerated stages may also be separately set.

The Live Line Working (LLW) needs a particular operational condition which means in the protection to trip with preset time delaying if Uo has appeared.

A three shot reclosing device is built in, these are a fast shot (FR), and two slow shot (1st SR, 2nd SR). Each shot may be made active and blocked. Each trip may be programmed to accelerated and delayed one, but the definite trip is always selective if there was not selective trip before it. The reclaim time of reclosing device is 5 s, fixed.

Two setting packs may be set on the device, in which all the settig values except the dead times may be preprogrammed in two variations so the setting of automatic device can be easily changed by hand or by remote control.

If the back up protection trips, the reclosing device gives a definite trip, and the recloser is blocked for the reclaim time.

If no fault after reclosing, the reclosing device goes back to the basic state.

The reclosing device may be controlled by blocking or permissig command. The device remembers to the blocking condition after supply voltage loss, as well.

If the reclosing device is blocked, the detection of relais I>>, I>, 3Io>> and 3Io> will trip with selective delaying.

Control commands can be put to the eight optical coupler inputs. Six of them fixed command (manual closing, reclosing blocked, reclosing permitted, LLW switch, reclosing stopped, reclosig device external start e.g. from pilot wire protection) while two command may be programmed.

Logical interconnection between the protection units as well as timers, and the output relais may be programmed by a software matrix.

A continuous and a periodical monitoring system is buit into the device. The continuous monitoring system checks the supply voltage presence, the healthness of the basic current circuits and the control circuits. The periodical monitoring system starts daily in a preset time, and when it is started by hand by the aid of the Control menu point of the Parametring basic menu. Both monitoring system gives alarm and automatic message appears on the LCD display when a fault is found.

The protection workings will be stored by an event log with 50 events memory, and by an event sequence recorder with 1 ms resolution and 300 events memory. The event log and the event sequence recorder may be read through series line.

The device can be completed with an entirely independent, self feeding overcurrent back up protection of type KZT. The back up protection is a classical electronic device set up with I.C.'s.
 
Technical data
 
 
Rated secondary current, In 1 A or 5 A (other value can be given when ordering)
Main C.T., primary current, settable
 50 to 1500 A, steps: 25 A
Zero sequence main C.T.,
primary current, settable
toroidal type C.T., ratio
50 to 1500 A, steps: 25 A
150/1 A
Overload capacity, continuous
1 s		 4×In
100×In (if In = 1 A)
50×In (if In = 5 A)
Dinamic current limit 100×In
Accuracy, overcurrent relais (over 50 %) ± 2 %
digital timers: (at step of 10 ms)
(at step of 1 ms)		 ± 3 ms
± 12 ms
Resetting ratio, overcurrent relais (on request, other value) 95 %
Overcurrent relais, setting range,
in per cent of main C.T. primary current
high and low setting overcurrent relais
zero sequence relais
in case of toroidal type C.T.

range
30 to 2500 %
10 to 104 %
10 to 104 ‰

step
5 %
5 %
5 ‰
Timers, setting range
current relays
FR dead time
1st and 2nd SR

0 to 60000 ms
0 to 60000 ms
0 to 600 s

10 ms
10 ms
1 s
Reclosing reclaim time (fixed) 5 s
External communication RS 232/optical fibre cable
External communication, transfer speed (BaudRate) 150 to 19200 Baud steps: 2 times
Daily automatic self check, starting time 0 to 23 hour 59 minute, step: 1 minute
Automatic self check, blocking setting to 60 minute
Output relais number
programmable by software matrix		 16 pcs print relais
10 pcs

Output contacts, electrical data:
rated switching voltage
continuous load current
making current
breaking current at 220 V dc,
pure conductive load
load of L/R = 40 ms
250 V
8 A
16 A

0.25 A
0.14 A
Auxiliary dc voltage (the same supply unit)
voltage tolerance 		220 V or 110 V
88 to 310 V
Permissive ambient temperature 0°C to 50°C
Insulation test (IEC 255) 2 kV, 50 Hz
5 kV, 1.2/50 ms
Disturbance test (IEC 255) 2.5 kV, 1 MHz
Electrostatic discharge test (ESD; IEC 801-2) 8 kV
Burst test, (IEC 801-4) 2 kV
 
Design, size
 
The digital complex overcurrent protection and automatic reclosing device of type DTIVA2-EP is an EuroProt device so it has designs of two different kinds. The one may be put to a standard cabinet of 19". The other design is an independent relay case. The outline sizes are as follows:

Width Height Depth
490 mm 250 mm 250 mm
 
Options
 
  • Disturbance recorder
  • Interface to a SCADA system
  • Output contacts with 4 A DC breaking capability
  • Sensitive earth fault relay on the middle voltage side
Data to be ordered
 
  • Protection type [DTIVA2-EP]
  • Rated current [1 A, 5 A]
  • Feeding of zero sequence relais [main C.T., toroidal type C.T.]
  • In case of toroidal type C.T., its ratio [150/1A or others]
  • Whether is directional earth fault protection needed?
  • Whether is Uo external voltage instead of Uo> external relay to the relay connected?
  • Whether is the logical (d.c.) busbar protection contact an NC or NO type?
  • Options [if needed]