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Manual MRG3 GB 

Woodward 

TD_MRG3_09.08_GB_Rev.New 

49 

5.6.6  Trip delay or time multiplier for earth fault element 

 
(Similar to chapter 5.5.3). 
Flashing of the LEDs IE + 1 + > + t> upon this setting. 
 
Relay version MRG3-IER: 
This version including directional feature allows different adjustment of the tripping time for forward 
and backward faults. For this purpose, the display first shows the up to date tripping time for for-
ward faults. The LED that is marked by two arrows lights up in green. Thereafter, it is possible to 
change this forward setting value via push-buttons <+><-> and store it by pressing >ENTER>. After 
pressing the <SELECT> but-ton, the current setting value for backward faults is displayed. The 
LED that is marked by two arrows lights up in red. 
 
This backward setting value should be higher than the value set for forward faults to allow the pro-
tective de-vice to operate selectively at occurrence of forward faults. 
 
When setting tripping times for forward faults and backward faults to the same value, the relay will 
trip with the same time delay, i.e. without directional feature. 
 

5.6.7  Reset mode for tripping characteristics in earth current path 

 
(Similar to chapter 5.5.4).  
Flashing of the LEDs IE + 1 + > + t> upon this setting 
 

5.6.8  Pick-up value for earth faults resp. earth short circuit fast trips 

(Similar to chapter 5.5.5). 
Flashing of the LEDs IE + 2 + > upon this setting 
 

5.6.9  Trip delay for earth fault s resp. earth short circuit fast trips 

 
(Similar to chapter 5.5.6). 
Flashing of the LEDs IE + 2 + > + t> upon this setting 
 

5.6.10 COS/SIN-measurement 

 
Depending on the neutral-point connection of the protected system the directional element for the 
earth cur-rent path must be preset to cos 

ϕ

 (isolated mains) or sin 

ϕ

 (compensated mains) mea-

surement. 
By pressing <SELECT> the display shows "COS" resp. "SIN". The desired measuring principle can 
be selected by <+> or <-> and must be entered with password. Flashing of the LEDs IE + 1 + 2 
upon this parameterisation. 
 
 

 

Summary of Contents for MRG3

Page 1: ...MRG3 Generator protection with mains supervision time overcurrent protection and earth current supervision September 2008 Manual MRG3 Revision New...

Page 2: ...rves the right to update any portion of this publication at any time Information provided by Woodward Governor Company is believed to be correct and reliable However no responsibility is as sumed by W...

Page 3: ...4 Residual voltage 33 4 7 5 Behavior of MRG3 under different operating conditions 33 4 7 6 Blocking function set in compliance with requirements 33 4 8 Fault recorder 34 5 Operation and Settings 36 5...

Page 4: ...of the clock 52 5 9 Additional functions 53 5 9 1 Blocking of protection functions and assignment of the output relays 53 5 10 Indication of measuring values 55 5 10 1 Measuring indication for mains d...

Page 5: ...lays 74 7 8 Setting ranges and steps 75 7 8 1 System parameter 75 7 8 2 Parameter protection Voltage protection Frequency protection Frequency gradient 77 7 8 3 Time over current protection 78 7 8 4 E...

Page 6: ...tection with definite or inverse time characteristics integrated determination of earth fault direction for application to power system networks with isolated star point or earth fault compensation ER...

Page 7: ...erse RI Inverse RXIDG characteristic Reset mode selectable for inverse time characteristics Definite time element for short circuit fast trip Two step earth fault supervision Optionally sensitive watt...

Page 8: ...3 1 Connections 3 1 1 Connection Diagrams Figure 3 1 Connection diagram Mains decoupling The measuring circuits can optionally be star or delta connected see chapter 4 3 1 Figure 3 2 MRG3 I Connection...

Page 9: ...Connection diagram with time over current protection and earth fault protection Holmgreen circuit This connection can be used with three existing phase current transformers when combined phase and ear...

Page 10: ...Woodward Manual MRG3 GB 10 TD_MRG3_09 08_GB_Rev New Figure 3 5 Connection diagram with time over current protection and earth fault directional feature...

Page 11: ...esidual voltage U can be generated internally in the secondary measuring circuit The device shall then be en coded as described in chapter 3 1 8 Thus star connection of voltage transformers is imperat...

Page 12: ...Woodward Manual MRG3 GB 12 TD_MRG3_09 08_GB_Rev New Figure 3 7 Connection diagram with detection of the residual voltage...

Page 13: ...trans formers in isolated compensated gr ids is explained in chapter 4 7 3 3 1 3 Output relays The MRG3 is equipped with 5 output relays Apart from the relay for self supervision all protective funct...

Page 14: ...n phase U_L1 400V L2 Measuring range 0 600V in phase U_L2 L3 400V Measuring range 0 600V in phase U_L3 U_E 400V Measuring range 0 600V in phase U0 Based on the set value of the secondary transformers...

Page 15: ...08_GB_Rev New 15 Figure 3 9 Change over to of measuring range for phase voltages phase l1 and L2 Figure 3 10 Change over to of measuring range for phase voltage Phase L3 Selection of the measuring met...

Page 16: ...detection of the residual voltage based on the three star connected phase voltages adjust the code plug to 3PHA The code plug s default position is 1 1 3 1 9 Low high range of the digital inputs The M...

Page 17: ...Manual MRG3 GB Woodward TD_MRG3_09 08_GB_Rev New 17 3 2 Front plates Figure 3 12 Front plate MRG3 Figure 3 13 Front plate MRG3 IE...

Page 18: ...Woodward Manual MRG3 GB 18 TD_MRG3_09 08_GB_Rev New Figure 3 14 Front plate MRG3 IU0 Figure 3 15 Front plate MRG3 I...

Page 19: ...Manual MRG3 GB Woodward TD_MRG3_09 08_GB_Rev New 19 Figure 3 16 Front plate MRG3 IER Figure 3 17 Front plate MRG3 UO...

Page 20: ...side next to the LEDs The LEDs will light up red during parameterizing of the setting values next to their right side Remarks Due to the fact that there are a variety of protection functions it is no...

Page 21: ...ssible fault situation in the protected object The calculated actual current values are compared with the relay settings If a phase current ex ceeds the pickup value an alarm is given and after the se...

Page 22: ...al voltage of the input transformers Dependent on the application the input transformers can be connected in either delta or star The connection for the phase to phase voltage is the delta connection...

Page 23: ...time measurement of complete cycles whereby a new measurement is started at each voltage zero passage The in fluence of harmonics on the measuring result is thus minimized Figure 4 3 Determination of...

Page 24: ...he measurement of the rate of change of frequency df dt Precondition for this is a load flow via the mains coupling point At mains failure the load flow changing then spontaneously leads to an increas...

Page 25: ...pment Power relays are able to pick up within 200 ms but they cannot prevent power to rise to short circuit values too Since power changes are also caused by sudden loaded alternators the use of power...

Page 26: ...oduces a voltage difference U is built between Up and U1 Fig 4 4 Figure 4 4 Equivalent circuit for synchronous generators running in parallel with the mains Figure 4 5 Changement of the rotor displace...

Page 27: ...n case of mains failure or auto reclosing the generator suddenly feeds a very high consumer load The rotor displacement angle is suddenly increases and the voltage vector U1 changes its direction U1 F...

Page 28: ...he vector surge element occurs only if in case of a vector surge the vector surge angle exceeds the set value simultaneously in all three phases at the same time Application hint Although the vector s...

Page 29: ...supply for internal requirements is endangered and a subsequent synchronized changeover to the mains can only be done after manual reset of the over current protection To avoid such a situation the a...

Page 30: ...rrent transformers supplying the relay Earth faults beyond the current transformers i e on the consumer or line side will not be detected Figure 4 9 Generator stator earth fault protection 4 7 2 Syste...

Page 31: ...er connections see Table 4 1 Total current can be measured by connecting the unit either to a ring core C T or to current trans formers in a Holmgreen circuit However maximum sensitivity is achieved i...

Page 32: ...age UE the ER XR relay type determines whether the line to be protected is earth faulted On non earth faulted lines the capacitive component Ic a of the total current precedes the residual voltage by...

Page 33: ...free pro grammable free pro grammable free pro grammable 2 blocking input is released released instantane ously released instanta neously released after 1 s released after 5 s released after 5 s 3 su...

Page 34: ...n the complete memory is divided into the relevant number of par tial segments If this max number of fault event has been exceeded the fault recorder blocks any further recordings in order to prevent...

Page 35: ...ach memory segment has a specified storage time which permits setting of a time prior to the trigger event Via the interface RS485 the data can be read and processed by means of a PC HTL PL Soft4 The...

Page 36: ...urrent in L2 Apparent current in L3 Residual voltage U0 Earth current Active component EP Reactive component EQ Angle IE and U0 SELECT RESET one time for each value U L1 U L2 U L3 U L1 L2 U L2 L3 U L3...

Page 37: ...ue in seconds SELECT RESET one time for each value U 1 U 1 t 5 4 1 overvoltage high set tripping delay of high set element setting value in setting value in seconds SELECT RESET one time for each valu...

Page 38: ...T one time for each value IE 1 t 5 6 6 Reset Mode 0s 60s SELECT RESET IE 1 t 5 6 7 Earth short circuit IE Tripping delay for IE in forward direction Setting value in Setting value in seconds SELECT RE...

Page 39: ...t SELECT RESET for 3s 5 7 1 Blocking EXIT until max setting value until min setting value LED of blocked parameter MR allg Save parameter SAV ENTER MR allg Save parameter SAV ENTER for aprrox 3 s MR a...

Page 40: ...for Indication of measured values as primary values on the display has to be set to SEK see chapter 5 3 2 With the aid of this parameter the MRG3 is capable of recognizing whether the calculation has...

Page 41: ...adapted FFT algorithm requires the nominal frequency of the object to be protected as a pa rameter for correct digital sampling and filtering of the input currents By pressing SELECT the display shows...

Page 42: ...e 5 2 Function of the digital inputs With the setting B_S2 the blocking input D8 E8 is used as parameter set change over switch With the setting R_S2 the reset input D8 E8 is used as parameter set cha...

Page 43: ...nd in the range of 0 04 s to 50 s and can be stored with the push button ENTER When setting the tripping delay to EXIT the value is infinite meaning only warning no tripping Note When adjusting the co...

Page 44: ...epends upon the number of set measuring repeti tions T periods and amounts to T tf min 2 49 T 1 20 ms 50 69 T 49 50 ms 1 s 70 99 T 69 100 ms 2 s When setting the tripping delay to EXIT by pressing pus...

Page 45: ...surge supervision is set a value in angular degree is indicated at the display The pickup value requested can be adjusted by pushbuttons and in the range of 2 to 22 LED _df lights up green during thi...

Page 46: ...haracteristic the LEDs l 1 t for tripping time and time factor setting t will flash up This warning signal is an indication for the user to align the tripping time and or the time factor to the modifi...

Page 47: ...n at recurring fault current 5 5 5 Pick up value for high set element The current setting value of this parameter is related to the generator s rated current of the relay and is indicated in When the...

Page 48: ...tor s nominal earth fault current For the relay version MRG3 IER the indicated value relates to the effective portion of the earth current for compensated grids cos procedure or to the reactive portio...

Page 49: ...o operate selectively at occurrence of forward faults When setting tripping times for forward faults and backward faults to the same value the relay will trip with the same time delay i e without dire...

Page 50: ...e currents have dropped to 2 x IN within tCBFP The relay that is as signed the failure protec tion function will drop after expiry of no more than 2 54 s The LEDs CB t will be flashing upon this param...

Page 51: ...e that the fault recorder is triggered although there is no more memory available If the respective partition was defined as not being over writeable and the maximal number of rec orded disturbance ev...

Page 52: ...m 00 day d 00 Time hour h 00 minute m 00 second s 00 The clock starts with the set date and time as soon as the supply voltage is switched on The time is safe guarded against short term voltage failu...

Page 53: ...Over current NO_B I 1 I Short circuit BLOC I 2 U0 Residual voltage step 1 NO_B U0 1 U0 Residual voltage step 2 NO_B U0 2 IE Earth current step 1 NO_B IE 1 IE Earth current step 2 NO_B IE 2 tCB Circui...

Page 54: ..._ _ U 2 tU Tripping X 1 _ _ _ U 2 t f1 Alarm _ _ _ _ f 1 tf1 Tripping X 1 _ _ _ f 1 t f2 Alarm _ _ _ _ f 2 tf2 Tripping X 1 _ _ _ f 2 t f3 Alarm _ _ _ _ f 3 tf3 Tripping X 1 _ _ _ f 3 t Tripping X 1 _...

Page 55: ...rk system s quality Always the highest and lowest values of each cycle are measured and stored until the next reset refer to chapter Reset 5 10 9 Min max frequency measuring The MRG3 ascertains the ac...

Page 56: ...as follows Indication as Range Unit Secondary voltage 000V 999V V Primary voltage 00V 999V 1k00 9k99 10k0 99k0 100k 999k 1M00 3M00 V kV kV kV MV Table 5 6 Units of the display 5 10 4 Indication of va...

Page 57: ...for rated transformer current 2kA and up Earth current Indication as Range Unit Secondary current Active portion IP Reactive portionl IQ 000 15 0 00 15 00 15 x In x In x In Primary earth current 000...

Page 58: ...iately switched off after tripping further fault data will be recorded The MRG3 is provided with a fault value recorder for max 16 fault occurrences In the event of ad ditional trippings always the ol...

Page 59: ...ping time in of tI tI I 1 t Residual voltage U0 U E Earth current Earth current active portion Earth current reactive portion IE IE_EP IE_EQ IE IE EP IE EQ Expired tripping time in of tIE tIE E 1 t Ci...

Page 60: ...same effect as the SELECT RESET push button see also communication protocol of RS485 interface Automatic Reset At each excitation of a protection function The display can only be reset when a pickup...

Page 61: ...e activate the two steps Press the push button ENTER thus entering into the setting mode Now set the parameters U and U to EXIT to block the under voltage functions After that press the SELECT RESET f...

Page 62: ...l voltages will be measured and evaluated Delta connection Phase to phase voltages will be measured and evaluated To assure an efficient operation of the relay the adjusted rated frequency f 50 60 Hz...

Page 63: ...MRG3 relay a three phase voltage source with adjustable voltage and frequency is required Figure 6 1 shows an example of a three phase test circuit ener gising the MRG3 relay during test The three pha...

Page 64: ...ures only the fundamental component of the input signals the harmonics will be rejected by the internal DFFT digital filter Whereas the RMS metering instrument measures the RMS value of the input sign...

Page 65: ...ncy functions can be tested in the similar manner as in chapter 6 4 6 for over under voltage functions 6 4 8 Checking of the vector surge function Note With the help of an advanced relay test equipmen...

Page 66: ...er and voltmeter class 1 or higher auxiliary voltage source supply with the voltage corresponding to the rated data pn the type plate single phase alternating current source adjustable from 0 to 4 x U...

Page 67: ...icated measured value can now be checked by means of an ammeter For a relay with rated current In 5A for example a secondary current impression of 1A should be indicated on the display with about 0 2...

Page 68: ...ave a deviation of less than 3 of the set value or 10 ms DEFT Accuracy for inverse time cha racteristics refer to EN60255 3 Repeat the test on the other phases or with the inverse time characteristics...

Page 69: ...6 4 shows an example of a single phase test circuit with adjustable voltage and current test ing a re lay with directional feature one of the input voltage terminals B1 A2 shall be applied to the rela...

Page 70: ...e similar manner as the secondary in jection test described above With the difference that the protected power system should be in this case connected to the installed relays under test on line and th...

Page 71: ...t to pickup ratio U U 99 U U 101 Returning time 60 ms Time lag error class index E 10 ms Minimum operating time 40 ms 7 1 1 Influences on the voltage measurement Auxiliary voltage in the range of 0 8...

Page 72: ...influences can be measured Frequency Within the range from 0 9 f fN 1 1 0 2 Hz only the first harmonic is evaluated Influences on delay times no additional influences can be measured 7 4 Measuring in...

Page 73: ...0 1 VA Thermal withstand capability In current circuit dynamic current withstand one halfwave 250 x IN for 1 s 100 x IN for 10 s 30 x IN continuously 4 x IN Dropout to pickup ratio MRG3 IE 95 MRG3 IE...

Page 74: ...he output relays have with the following characteristics Maximum breaking capacity 250 V AC 1250 VA continuous current 5 A For DC voltage ohmic L R 40 ms L R 70 ms 300 V DC 0 2 A 60 W 0 13 A 40 W 0 12...

Page 75: ...nal generator voltage 0 001 0 05 0 20 0 002 0 20 0 50 0 005 0 50 1 00 0 01 1 00 2 00 0 02 2 00 5 00 0 05 5 00 10 0 0 1 10 0 20 0 0 2 20 0 50 0 0 5 50 0 100 1 100 200 2 200 500 I_L1 L2 L3_prim sek 0 00...

Page 76: ...IE_prim sek 0 002 50 0 kA Primary nominal trans former current for earth fault 0 001 kA 0 002 0 200 0 002 kA 0 200 0 500 0 005 kA 0 500 1 00 0 01 kA 1 00 2 00 0 02 kA 2 00 5 00 0 05 kA 5 00 10 0 0 1...

Page 77: ...25 ms T T 2 99 periods 1 2 99 f1 f3 30 49 99 EXIT 50 01 70 Hz 1 40 59 99 EXIT 60 01 80 Hz 2 0 1 30 00 47 90 0 01 48 00 49 99 0 01 50 01 52 00 0 1 52 10 70 00 0 1 40 00 57 90 0 01 58 00 59 99 0 01 60...

Page 78: ...ar Normal Inverse Type A Very Inverse Type B Extremely Inverse Type C RI Inverse Long Time Inverse NINV VINV EINV RINV LINV 0 05 10 EXIT inverse time 0 01 0 05 0 5 0 02 0 5 1 0 0 05 1 0 2 0 0 1 2 0 5...

Page 79: ...p A Very Inverse Typ B Extremely Inverse Typ C RI Inverse Long Time Inverse RXIDG Kennlinie NINV VINV EINV RINV LINV RXID 0 05 10 EXIT 0 05 1 0 EXIT only RXIDG inverse time 0 01 0 05 0 5 0 02 0 5 1 0...

Page 80: ...0 1 20 45 3 of the set value or 0 3 IN tIE V tIE R 0 1 300 s EXIT 0 1 0 1 5 0 0 2 5 0 10 0 0 5 10 20 1 0 20 50 2 0 50 100 5 0 100 200 10 0 200 300 3 or 80 ms Table 7 5 Earth fault supervision with dir...

Page 81: ...the set value or 1 from UN tU0 0 04 300 s EXIT 0 02 0 04 1 0 0 05 1 0 2 0 0 1 2 0 5 0 0 2 5 0 8 5 0 5 10 20 1 0 20 50 2 0 50 100 5 0 100 200 10 0 200 300 1 or 20ms Table 7 6 Residual voltage protecti...

Page 82: ...le for MRG3 I MRG3 IU0 MRG3 IE MRG3 IER 10 00 s 5 00 s 2 50 s 1 25 s 50 Hz 8 33 s 4 16 s 2 08 s 1 04 s 60 Hz Pre Trigger time 0 1 s maximum 10 00 s 50 Hz 0 1 s maximum 8 33 s 60 Hz FR Storage of recor...

Page 83: ...o IEC 255 4 or BS 142 Normal Inverse Type A 0 14 1 Very Inverse Type B 13 5 1 Extremely Inverse Type C 80 1 Long Time Inverse 120 1 RI Inverse Time 1 0 339 0 236 RXIDG characteristic 5 8 1 35 Where t...

Page 84: ...7 1 Normal Inverse Typ A Figure 7 2 Very Inverse Typ B 1 2 3 4 5 6 7 8 910 20 I IS 0 1 1 10 100 1000 t s tI 0 05 0 1 0 2 0 3 0 4 0 5 0 6 0 8 1 0 1 4 2 0 3 0 4 0 6 0 8 0 10 0 1 2 3 4 5 6 7 8 910 20 I I...

Page 85: ...yp C Figure 7 4 RI Inverse 1 2 3 4 5 6 7 8 910 20 I IS 0 01 0 1 1 10 100 1000 t s tI 0 05 0 05 0 1 0 1 0 2 0 3 0 4 0 5 0 6 0 8 1 0 10 0 1 4 2 0 3 0 4 0 6 0 8 0 1 2 3 4 5 6 7 8 910 20 I IS 0 1 1 10 100...

Page 86: ...DG characteristic 1 2 3 4 5 6 7 8 910 20 I IS 0 1 1 10 100 1000 10000 t s tI 1 0 2 0 10 0 8 0 6 0 5 0 4 0 3 0 0 8 0 6 0 5 0 4 0 3 0 2 0 1 0 05 1 2 3 4 5 6 7 8 910 20 30 40 506070 I IS 0 01 0 1 1 10 t...

Page 87: ...urrent I1 I5 Earth fault protection 1 Earth current 1 A rated current 5 A rated current Residual voltage E1 E5 U0 Directional feature in earth path 1 Residual voltage supervision R Housing 12TE 19 rac...

Page 88: ...code Relay functions Password Date Adjustment of the parameter Adjustment of date and time Relay type Actual settings Symbol LED Function MRG3 MRG3 I MRG3 UO MRG3 IE MRG3 IOU MRG3 IER Year settings Y...

Page 89: ...nal transformer voltage in phase kA X X X X sek I_L1 L2 L3 rated I L1 L2 L3 2 Primary nominal generator voltage in phase kA X X X X sek U0_prim U E 1 Primary residual voltage kV X X X sek U0_sec U E 2...

Page 90: ...d overvoltage element high set X X X X X x 120 tU U 2 t Tripping delay for the 2 nd overvoltage element S X X X X X X 0 04 T f Frequency measuring repe tition in periods perio ds X X X X X X 4 f1 f 1...

Page 91: ...idual voltage element X X 10 U0 t U0 2 t Tripping delay for the 2 nd residual voltage element s X X 0 1 IE IE 1 Warning tripping of the IE element X X warn IE IE 1 Pickup value for earth over current...

Page 92: ...MRG3 IER RS Slave address of the serial interface X X X X X X RS1 RS Baud Rate Bau d X X X X X X 9600 RS Parity Check X X X X X X even Blocking function Relay type Default settings Actual settings Sym...

Page 93: ...sl U 2 t X X X X X X X f1 Alarm f 1 X X X X X X f1 Ausl f 1 t X X X X X X X f2 Alarm f 2 X X X X X X f2 Ausl f 2 t X X X X X X X f3 Alarm f 3 X X X X X X f3 Ausl f 3 t X X X X X X X Ausl df X X X X X...

Page 94: ...DI_2 input Default set tings Actual settings Default settings Actual settings Low plugged X X High not plugged Measuring range residual voltage Code jumper Measuring voltage range phase U_L1 Measurin...

Page 95: ...3 D01 1 00 mit SEG ProOpenData Protokoll MRG3 I D02 1 00 MRG3 U0 D03 1 00 MRG3 IE D04 1 00 MRG3 IU0 D05 1 00 MRG3 IER D06 1 00 MRG3 M D51 1 00 mit Modbus Protokoll MRG3 I M D52 1 00 MRG3 U0 M D53 1 00...

Page 96: ...e mail kemp electronics woodward com Service Phone 49 0 21 52 145 614 Telefax 49 0 21 52 145 455 e mail kemp pd woodward com Woodward SEG GmbH Co KG Krefelder Weg 47 D 47906 Kempen Germany Postfach 1...

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