DIFFERENTIAL RELAY

Differential relays are simple, reliable and widely used type of protection scheme that are very much suitable for electrical system or equipment protection. The relays use pilot wires to find the ‘difference’ but the pilot wire itself creates so many problems. To eliminate the problems, in this paper an IoT based wireless current differential protection system is proposed based on Wi-Fi communication and is implemented as a small project work and has also been tested for the protection of a pseudo power system network. The work done here is a small project but with a small update this can be used for real life power system protection.

An application of phase-angle-difference based algorithm with percentage differential relays is presented in this paper. In the situation where the transformer differential relay is under magnetizing inrush current, the algorithm will be utilized to block the process. In this study, the technique is modeled and implemented using Simulink integrated with MATLAB. The real circuit model of power transformer and current transformers are considered in the simulation model. The results confirmed the effectiveness of the technique in different operation modes; such as, magnetizing inrush currents, current transformers saturation and internal transformer faults.

Differential relays are simple, reliable and widely used type of protection scheme that are very much suitable for electrical system or equipment protection. The relays use pilot wires to find the 'difference' but the pilot wire itself creates so many problems. To eliminate the problems, in this paper an IoT based wireless current differential protection system is proposed based on Wi-Fi communication and is implemented as a small project work and has also been tested for the protection of a pseudo power system network. The work done here is a small project but with a small update this can be used for real life power system protection. Keywords-Differential relay, Compact Module, IoT, Wi-Fi, Pilot wire, Adafruit IO. , ,1752'8&7,21 ,Q .HYLQ $VKWRQ ILUVW LQWURGXFHG WKH FRQFHSW RI ,QWHUQHW RI 7KLQJV ,R7 LQ >@ ,R7 LV WKH LQWHUFRQQHFWLYLW\ RU LQIRUPDWLRQ VKDULQJ EHWZHHQ UHDO RU SK\VLFDO REMHFWV RU WKLQJV >@ 7KLV LV WKH LQWHUFRQQHFWLRQ ³LQWHUQHW´ RI UHDO OLIH REMHFWV ³WKLQJV´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µIDXOW ¶ 3LORW ZLUHV DUH WKH FRQQHFWLQJ ZLUHV EHWZHHQ WKH WZR RU PRUH GLIIHUHQWLDO TXDQWLW\ PHDVXULQJ GHYLFHV &7V 7KH µSLORW ZLUHV ¶ DUH XVHG WR GHWHUPLQH WKH GLIIHUHQFH EHWZHHQ WKH HQWHULQJ DQG OHDYLQJ FXUUHQWV ,Q IDXOW WKH µGLIIHUHQFH ¶ FXUUHQW IORZV WKURXJK WKH RYHU FXUUHQW UHOD\ DQG WKH UHOD\ RSHUDWHV %XW XQIRUWXQDWHO\ WKH SLORW ZLUH LWVHOI LV D SUREOHP 7KH LPSHGDQFH RI WKH SLORW ZLUH LV D SUREOHP 7KLV LPSHGDQFH HYHQ LQ µQR IDXOW ¶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µLPSOHPHQWHG ¶ DV D SUDFWLFDO SURMHFW RU SURWRW\SH XVLQJ $UGXLQR &XUUHQW VHQVRU 5HOD\ ERDUG DQG 1RGH0FX :L)L PRGXOH)LJ 6LPSOH $UUDQJHPHQW IRU &XUUHQW 'LIIHUHQWLDO 5HOD\ ,, /,67 2) &20321(17 A. Arduino Uno R3 $UGXLQR LV QRWKLQJ EXW D PLFURFRQWUROOHU EDVHG GHYHORSPHQW ERDUG ZLWK VRPH H[WHQGHG XVHU IULHQGO\ DQG VLPSOHU FKDUDFWHULVWLFV B. Current Sensor ACS712 (30 A) 7KH &XUUHQW VHQVRUV LQ WKLV SURMHFW DUH SOD\LQJ WKH UROH RI &7V XVHG WR PHDVXUH FXUUHQW RQ WKH ERWK VLGHV RI WKH SURWHFWHG ]RQH DV LQ)LJ 7KH &XUUHQW VHQVRUV $&6 ZRUN RQ WKH EDVLV RI +DOO (IIHFW 6R IURP WKH VHQVRU ZH JHW D YROWDJH RXWSXW SURSRUWLRQDO WR WKH LQSXW FXUUHQW C. ESP8266 NodeMCU Lua WiFi module (ESP-12E) 7KLV LV DOVR D GHYHORSPHQW ERDUG OLNH WKH $UGXLQR EXW ZLWK OHVV FDSDELOLW\ 7KH VSHFLDO IHDWXUH RI WKLV LV WKH LQWHJUDWHG RQ ERDUG (63 :L)L PRGXOH 7KLV PRGXOH DOORZV FRPSOHWH :L)L FRQQHFWLYLW\ DQG FRPPXQLFDWLRQ D. Relay Module (5 V) 5HOD\ PRGXOHV DUH LPSRUWDQW IRU PDNLQJ DQG EUHDNLQJ HOHFWULFDO FLUFXLWV PDJQHWLFDOO\ 7KLV PRGXOH LV FRPSRVHG RI 5HOD\ DQG &LUFXLW EUHDNHU E. Adafruit IO Web Server 6HUYHU LV D SODFH ZKHUH ZH FDQ VWRUH GDWD DQG XVH WKH VWRUHG GDWD ZKHQHYHU QHHGHG :HE VHUYHU LV DQ LQWHUQHW FRQQHFWHG VHUYHU WKDW FDQ EH DFFHVVHG WKURXJK LQWHUQHW 0G)DWLQ ,VKUDTXH 0G 0DPXQXU 5DVKLG 6N$ 6KH]DQ

PCS-985G can be applied for large-scale turbo-dynamo, gas-turbine generator and nuclear power generator with different connections mode
PCS-985G takes fully into account maximun configuration of large-scale generator, and suits the generator with capacity of 100MW or above

The quality of an electric power system is measured by its continuity of service, good control and maintenance. The good continuity of service can be obtained if all the components of power systems can operate well in every situation and condition, either in normal or in abnormal condition. In abnormal condition, the protection system has an important role in detecting every disturbance and disconnecting the disturbed parts from the system. The power transformer is the main component in a substation. The disturbances in the transformer should be isolated so as not to disturb the system during distribution of the electric power to other load. The differential relay on the power transformer is a protection relay to detect internal disturbance. This paper discusses the setting and mismatch error of differential relay in substation of Central Duri at switchgear #3 at PT Chevron Pacific Indonesia (PT CPI).

PT. Badak NGL is a company that operates the largest LNG Plant in Indonesia with maximum LNG (Liquefied Natural Gas)
production capacity 22.5 MTPA and LPG (Liquefied Petroleum Gas) production capacity 1.0 MTPA from eight (8) trains. The
company operates 22 high voltage induction motors which the motor capacity is 3.3 MW and operated in 13.2 kV level voltage to pump sea water for cooling system in LNG process production.
In 2007, PT Badak NGL implemented retrofit relay project by installing several relays at sea water pump motors with numerical type. After installation, the motors have repetitive nuisance trip which this problem impact to process production.
The relay data informed that differential protection was activated with stator winding problem, but after conducting
verification and further electrical tests on the stator winding condition, resulted that the winding motor is in good condition.
Further analysis had been performed by evaluating differential relay setting to overcome motor trip in the future.
On this paper, PT Badak NGL will share experience how to overcome the nuisance trip on healthy motor by evaluating
differential protection relay setting.

In this research work, fuzzy logics based differential protection scheme is proposed for power transformer. Membership functions are developed from voltage, frequency and currents at primary side and secondary side of the power transformer. The proposed protection scheme senses the operating conditions and gives trip or no trip signal to the circuit breaker from the fuzzy inference of the small, medium and high values of the membership functions. Simulation results of various operating conditions, shows that the proposed differential relay is reliable, fast and is able to discriminate between internal faults, external faults and magnetizing inrush current. Results also demonstrate selective phase switching and auto-reclosing function of the protection scheme. Fuzzy logics based protection scheme is modeled in MATALAB-SIMULINK environment. Index terms-Auto re-closing, fuzzy inference, fuzzy logics, membership functions, selective phase switching.

Differential relays are widely used in the Power networks as a protection for power transformers, bus bars and generators. This paper aims to model one typical differential relay in the SIMULINK environmental. This model has been simulated in the MATLAB program and the results confirmed truth of the proposed model. Also, this model is used to build differential relay block in MATLAB software. Since MATLAB software does not have a differential relay block, this block can be used in other power system's simulations as
a differential relay.