Capacitor bank controller and protection using VAMP 260 power monitoring unit and VAMP 40 protection relay

Transcription

1 Applicati Note Date: / AN40.EN001 bank ctroller and protecti using VAMP 260 power mitoring unit and protecti relay The new feeder and motor protecti relay has many applicatis in the electrical distributi and industrial markets. One of the applicatis is for capacitor, filter and reactor bank protecti. The use and applicatis are described in this article. Unbalance protecti The relay has 5 current inputs as well as a single voltage input. Normally two of these inputs can be used for earth or residual current inputs. In double star unearthed capacitor bank applicatis, these inputs can be used for unbalanced current detecti. The unbalance protecti is measured with a dedicated current transformer between the star points of the banks as shown in the figure below. The unbalance current is not affected by system unbalance. However, due to capacitor manufacturing tolerances, some amount of natural unbalance current exists between the star points. In the, this unbalance current is compensated so that the net current measured becomes zero. This compensati is triggered manually at commissiing. The phasors of the unbalance current and e phase current are recorded (the latter for a polarising to zero measurement). As the initially existing unbalance current is compensated to zero in the relay, the unbalance setting can be very sensitive. Should the unbalance current change due to failure in the bank, this functiality can be used to also located the branch of the faulty element which would typically be a blown fuse. Two current stages can be set for unbalance alarm and trip respectively. Following a blown fuse, a time setting would determine how lg the unbalance cditi has to prevail before it is determined to be a faulty fuse. After a fuse failure has been detected, new compensati is added automatically so that the unbalance current seen by the relay yet again becomes zero. A faulty element counter is also increased simultaneously. The user can set the number of tolerable faulty elements before a trip is initiated. Five unbalance inputs Figure Applicati 4, 6, and 8 also measures phase currents into the capacitor banks. However, the three phase inputs can also be used for unbalance detecti, making it possible to have up to five unbalance inputs into a single relay. This is achieved with another novel feature of the which ctains up to eight programmable stages or virtual protecti elements. This makes it possible to define additial protecti elements of any available type within the relay, hence making it possible to have five unbalance current inputs rather than phase currents. Of course, without a phase current input there would not be any current polarisati. 1/7

2 Applicati 1 bank unbalance protecti for a fixed bank 48 Ist> Frt T2 X2:1 2 4 Applicati1 Applicati 2 bank unbalance protecti for an automatic bank (25 steps) X 2:1 5 X 2:1 6 X 1 X 4 X 6:1 X 6:2 X 6:3 X 6:4 X 6:5 X 6:6 X 6:7 X 6:8 X 6:9 X 6:1 0 X 6:1 1 X 6:1 2 X 6:1 3 X 6:1 4 Pr. stage 1: 1 alarm Pr. stage 2: 1 trip Pr. stage 3: 1 alarm Pr. stage 4: 1 trip Pr. stage 5: 1 alarm Pr. stage 6: 1 trip Applicati 2 2/7

3 Applicati 3, 5 and 7 bank overcurrent, earthfault, overload and unbalance protecti for a fixed bank 1 Frt 0 > X6 :2 0 >> Applicati3,5,7 Applicati 4, 6, and 8 bank overcurrent, earthfault, overload and unbalance protecti for an automatic bank (2 steps) 67N Frt > >> Applicati4,6,8 3/7

4 Applicati 9,11,13 and 15 bank unbalance voltage, overcurrent earthfault and overload protecti for a fixed bank Frt R emote > >> 59N U 0 > U 0 > 4 X9: 1 DI 1 X9: 2 DI X9: 4 DI 2 X9: 5 Di 2 Applicati9,11,13,15 Applicati 17 bank over/undervoltage protecti with unbalance protecti for a fixed bank 27 U< Frt > >> 59 U> U>> U>>> U<< U<<< Applicati 17 4/7

5 Applicati 18 bank over/undervoltage protecti with unbalance protecti for an automatic bank (25 steps) 67N > >> 59 U> 27 U< 48 Ist> 47 I2>> 59N 66 N> Auto Reclose Autorecloser matrix Applicati 21 Cnecti of temperature alarm and trip 1 Frt 0 VSE 003 > 0 >> PT 100 Applicati 21 RS485 ADAM 5/7

6 P.F ctroller applicati Twostage clock ctrolled power factor ctroller The following figure demstrates the use of the VAMP 260 for ctrolling capacitor switching. In such an applicati the VAMP 260 could be used to ctrol reactive power compensati depending the time of the day or to other measured criteria. Of course this ctrol could be used in isolati or combined with voltage ctrol to provide a very flexible shunt bank ctroller, be it a reactor or capacitor. With the aid of an RTD input, temperature measurements could also be used for protecti and/or ctrol applicatis. VT U 12 U U I I I VAMP 260 Programmable clock (Since sw v5.60) Timer 1 0 Block Matrix Mday Time 01:39:00 Timer 1 On 05:58:00 Timer 2 Off 23:58:00 Timer 3 Timer 4 Mode Daily Alarm stage 1 Coupling tanϕ > Limit Delay 120 s Hysteresis 15% Alarm stage 2 Coupling tanϕ > Limit Delay 240 s Hysteresis 10% Alarm stage 3 Coupling Limit Delay Hysteresis Low block Alarm stage 4 Coupling Limit Delay Hysteresis Low block tanϕ < s 15 % tanϕ < s 10 % alrm1 alrm2 alrm3 alrm4 T2 A2 A3 alrm5 X312 X313 X213 X215 X314 X315 X210 X212 bank 1 ON bank 2 ON bank 1 OFF bank 2 OFF 1) Values in bold are user cfigurable. 6/7

7 Power factor ctroller Time of day and power factor criteria of the clock ctrolled power factor ctroller Q 06:00 0:00 and PF < 0.92 ind. => bank ON ind. P REVERSE 0.92 FORWARD cap. 00:00 6:00 and PF < 0.92 cap. => bank OFF. Time of day 00:00 6:00 Power factor < 0.92 cap. tanj < Timer1 T2 OFF 00:00 6:00 00:00 6: cap ind. < 0.92 ind > :00 24:00 < 0.92 cap. < :00 24: cap ind. 06:00 24:00 < 0.92 ind > ON Summary The relay has many more measured quantities and functialities than the few described in this article. As VAMP places the highest priority userfriendliness, all these functialities are extremely easy to apply. It can be ccluded that the can be used its own or in combinati with the VAMP 260 to provide comprehensive capacitor bank protecti and/or ctrol. K e yw ords : Capaci tor bank ctrol l e r, Capaci tor bank p rote cti rel ay, Capaci tor b ank u nbal ance p rote cti, Capaci tor bank short ci rcui t p rote cti, Capaci tor bank p.f. p rote cti VAMP Ltd Visiting Address: Tel: ISO 9001:2000 P.O.Box 810 Vaasa Airport Park Fax: certified company FI65101 VAASA Yrittäjänkatu 15 vamp@vamp.fi Finland Vaasa, Finland We reserve the rights to product alteratis without prior notice. Copyright Vamp Ltd. All trademarks are the property of their respective holders 7/7