SAI-3580D digital transformer protection devices
I. Overview
SAI-3580D applies to 66KV and below voltage dual ring transformer differential meet the requirements of composite voltage lockout overcurrent protective device for the basic configuration of the transformer . Protection devices can be installed in the switch cabinet in place , but also set the screen installed in the control room.
The main protection configuration features :
● differential speed off
● ratio of the second harmonic restraint differential
● CT disconnection locking differential
● cooling fault delay exports
● time limit of three sections of the composite voltage lockout directional overcurrent protection (Ⅰ, Ⅱ segment available with directions )
● three sections of ground zero sequence protection (Ⅰ, Ⅱ two time segments , Ⅲ segment selector jump )
● ungrounded zero sequence protection ( Sec time period setting zero sequence overvoltage protection , overcurrent protection gap zero sequence )
● Protect export control word using the trip mode choice , flexible tuning
● overload alarm
● reclosing
● Independent acceleration section
● Current Start ventilation
● current blocking voltage regulator
Control Function Deployment
● 9 -way remote communication open into the strong current collection
● device power failure alarm , emergency signal device , the device alarm signal
● breaker remote switching
● analog telemetry : Ia, Ib, Ic, Ua, Ub, Uc, P, Q, COSθ, F
● 2 -way pulse input
● 1 -way GPS time
Second, the principle that the protection of
2.1 , the differential speed off
When the current is greater than either move away from the differential speed off the setting value , the total exports of the relay action . Under severe fault conditions for the occurrence of rapid removal of the transformer in the transformer differential area. Should be able to determine the value of the differential speed to escape the maximum inrush current external fault current imbalance and airdrop transformer , and taking into account the current transformer saturation factor , generally take 6 to 12 times the rated current.
Its operating conditions are as follows :
Which is a differential current Id , Isd to determine the value of the differential speed
2.2 , the ratio of the differential
Conventional rate differential principle , its movement equation is as follows :
Id> Iqd Ir ≤ Ig
Id-Iqd> Kcd * (Ir-Ig) Ig0.7 (Ir-2.5Ie) Ir> 2.5Ie
Kcd braking coefficient is the ratio
Iqd starting value for the differential current
Id for the differential current Id = | I1 + I2 |
Ir brake current Ir = 0.5 (| I1 | + | I2 |)
Because each side of the current transformer can be Y / △ adjusted by software , it can be all- star external wiring . All- star wiring to reduce the current transformer secondary load and improve the performance of the current transformer of great benefit .
Its action curve as shown below:
Recommended that the elements of inflection current Ig is set to 1.0 times the rated current of the high-pressure side to ensure the inter-turn short circuit current is less than the rated current of the brake that Ir < when Ie, no braking action .
Differential current threshold criterion should not be too small , it is recommended to take Iqd = (0.3 ~ 0.5) Ie.
Braking coefficient Kcd recommended ratio ranges from 0.3 to 0.7.
For dual ring becomes :
In the apparatus , the inflow side of the current transformer are positive direction , the phase difference is corrected automatically by the software . Each side of the current transformer transformers are used in star connection , and to point to the transformer for the same polarity.
2.3 , the second harmonic restraint
The use of three-phase differential current as a criterion in the second harmonic inrush current atresia . Action equation is as follows :
Id2> Kxb · Id
Which is a three-phase differential current Id2 in the second harmonic , Id for the corresponding three-phase differential current , Kxb braking coefficient for the second harmonic . Three-phase differential current in any phase as long as the above conditions are satisfied , all lockout -phase rate differential protection. Kxb generally taken to be between 10% to 30%.
2.4, CT disconnection alarm and lockout
CT has a broken latch or momentary alarm functions and differential current limit alarm function.
2.4.1 , the instantaneous disconnection CT
After starting rate differential , subject to instantaneous disconnection CT testing to ensure the flow is not due to poor break caused . CT is determined after the break , an alarm signal , reporting CT disconnection, by adjusting the control word can decide whether locking differential protection .
CT instantaneous disconnection determined in any of the following conditions is satisfied , the determination is not performed CT disconnection :
1 ) Before starting a side maximum phase current is less than 20% of the rated current side is not sentenced to the side ;
2) After starting phase current is greater than the maximum of 120% of rated current side ;
3 ) Start served as a side current increase over the previous start.
In the case of the above three conditions are not met, such as one side of the following conditions are satisfied , the penalty for CT disconnection :
4 ) is only one phase current is zero ;
5 ) The remaining two-phase currents are equal before the starting current.
2.4.2 , differential current limit alarm
If the difference is greater than the flow of high-pressure side of the rated current 15 percent , by determining the over 10s, an alarm signal. And reports differential current -limit , but not locking differential protection . This feature and the protective device AC sampling monitoring circuit.
2.5 , composite voltage lockout directional overcurrent
This device located three segments composite voltage lockout overcurrent protection, current and time of each segment value independently tuning, tuning control words were set to control these three paragraphs protection cast back . Ⅰ, Ⅱ segment can take direction atresia, the control word choice , the direction of the positive sequence voltage components using polarization direction of the components and elements connected in accordance with current starting mode . Directional element with memory function to eliminate the dead zone near the direction of the three-phase short-circuit elements . Directional element sensitivity angle is 45 degrees. Composite voltage components may choose to take the side of the control word , take each side contralateral or take . Composite voltage from low voltage and negative sequence voltage components or gates can be cast back by the control word choice . When one side of the transformer PT maintenance and normal operation, the control word to withdraw from the side by the pressure and direction of complex components.
2.6 , zero-sequence ( gap zero sequence ) overcurrent
For 110KV and above voltage class transformers need to set ground protection , according to three of the devices are equipped with grounding protection :
1 ) neutral grounding operation : Set zero sequence overcurrent protection has three sections , I, II , two each time segment , can take direction atresia ; Section III a time , as an option to jump exit ( eg jump connected to the same bus ungrounded running insulated transformer ) .
2 ) ungrounded operation : The device has a time period of two zero-sequence overvoltage trip for the first time exported to shorten the scope of failure , the second time were jumping on each side of the main transformer switch .
3 ) ungrounded operation : The device has a time period of two zero sequence overcurrent protection gap , the first time exports to shorten the trip for fault coverage , and the second time were jumping on each side of the main transformer switch .
2.7 , overload alarm
Over the three-phase load current monitor , which is the operating condition : Ia, Ib, Ic of any one phase is greater than the overload current value Ifh, by the delay signal .
2.8 , overcurrent start ventilation
Overcurrent start of three-phase current monitoring ventilation components , its operating conditions as : Ia, Ib, Ic overload any one phase is greater than the current value Iqdfl, by the delay exports.
2.9 , overcurrent latch regulator
Surge overcurrent latch element monitors the three-phase current, the operating condition is : Ia, Ib, Ic of any one phase is greater than the regulator setpoint latching Ibsty, the delay through the outlet .
2.10 , cooling failure delayed trip
Tuning control word choice whether to go through the cooling fault protection device tripping delay , the delay time can also be tuning . Cooling failure a high atresia without oil cooling fault contact is closed after the delay time to the trip ; cooling failure 2 by high oil temperature lockout, high oil temperature cooling fault contact and the contact is closed while the delay time to the trip after two way completely independent .
2.11 , non-power protection
Coming from the transformer body contact after SAI-3581F Verb non-power protection device , the output contacts to a group of empty SAI-358D main protection device event logging , and MMI will be recorded by the computer to upload to the background . Corresponds to the SAI-3581F non-power protection devices , choose what information needs to be non-power recorded by a soft cast back plate .
Tuning control word choice whether to go through a cooling fault protection device SAI-358D Main trip delay , the delay time can be tuning . After the delay is reached, the device outputs a paid trip contacts back to the SAI-3581F non-power protection devices.
2.12 , reclosing function
This feature is only applicable to the device corresponding circuit breakers, transformers contralateral not complete coincidence circuit breaker .
2.6.1 boot loop
1 ) protection trip starts
2 ) switch position does not correspond to start
Without corresponding start reclosing circuit, using only TWJ contact breaker position monitoring . Consider the design of many new substations, especially integrated automation station , may not have the manual operating handle , the devices are designed to avoid the use of manually operated handle contact , the use of the device when the hand jump STJ make contact to achieve reclosing atresia.
2.6.2 lockout condition
When combined bit coincidence circuit breaker charging time is 15 seconds ; charging process coincides with the green hair flash , often after being charged full green hair , no longer flashing. Reclosing of the device settings "discharge" conditions are:
1 ) After the control circuit break , automatic reclosing delay 10 seconds "discharge"
2 ) spring discharged high potential terminal , automatic reclosing delay 2 seconds "discharge"
3 ) jump contralateral breaker reclosing immediately "discharge"
4 ) coincide fail immediately "discharge"
5 ) Immediately after the first coincidence "discharge"
6 ) high potential terminal reclosing lockout , reclose immediately "discharge"
2.13 , acceleration
This feature is only applicable to the device corresponding circuit breakers, transformers contralateral unable to complete the circuit breaker tripped acceleration . The device includes a loop acceleration hands to accelerate and protect the acceleration of two , set up a separate acceleration cast back plate .
Hands together to accelerate the device manually closing the loop handle without external contacts to start the move mainly on account of the many current substation integrated automation system , the control panel has been canceled , the site is no longer installed manually operated handle, only a simple operation or installation of the handle .
Hands to accelerate the start condition for the loop :
1 ) the circuit breaker in the OFF position for more than 30 seconds
2 ) closing the circuit breaker into the opening , allowing time to accelerate expansion of 3 seconds
Protection accelerate acceleration mode after coincidence .
This device set up an independent overcurrent current value and the acceleration time constant, compared with the traditional protection , such practices become more flexible so that protection configuration .
2.14, PT break detection
The side of the PT disconnection :
One of the following three conditions are met, the device reported hair "PT disconnected " message and warning lights lit :
1 ) Three-phase voltages are less than 8V, a phase current is greater than 0.25A, sentenced to three-phase pressure loss .
2 ) three-phase voltage greater than 8V, the minimum line voltage is less than 16V, sentenced to two -phase PT disconnected.
3 ) three-phase voltage greater than 8V, the maximum and minimum line voltage line voltage difference is greater than 16V, determined to break the single -phase PT .
After the device detects the side PT break, back-up protection function has the following changes :
1 ) compound voltage lockout ( direction ) of the side overcurrent protection is automatically released composite voltage lockout, only through his side of the compound voltage lockout
2 ) the direction of composite voltage -current protection device is automatically released
3 ) upon voltage restoration , protection is automatically restored to normal.
2.15 , the data record
The device has a fault recorder function. Analog recording is available Iah, Ibh, Ich, Iam, Ibm, Icm, Ial, Ibl, Icl, 3I0, Ua, Ub, Uc, Ux, Ii0, the state can record the amount of breaker position , closing protection trip commands. All data records stored in FLASH RAM in the information data , the PC can be read. Recorded wave reports record is eight more than the total time for each recorded data capacity of 1S, separated into two records, motion capture and adjust the recording time. Events can be recorded no less than 1000 times. In addition to the device data recording system disturbances , but also recording device operation event status bit input quantitative event , change event and setting alarm events and other devices .
2.16 , remote telemetry, remote control
There are three main remote control : remote tripping normal operation and closing operation , grounding line remote tripping operation.
Remote measurements are mainly : Iah, Ibh, Ich, Iam, Ibm, Icm, Ial, Ibl, Icl, UA, UB, UC, UAB, UBC, UCA, COS ¢, P, Q, F and electrical degrees. All these quantities are calculated in real time at the local , real-time accumulation , three-phase active and reactive power calculation eliminates errors due to system voltage asymmetry generated , and the calculation is completely dependent on the network , accuracy of 0.5 .
Remote Communication are: 16 remote communication open into , remote communication device displacement and accident remote, and for recording the sequence of events , remote resolution of less than 2ms.
Third, tuning and event information devices
3.1 , setting the value of the list :
No. Name Symbol setpoint setting range Unit Remarks
A control word a KG1 0000 ~ FFFF no see control word description
A control word two KG1 0000 ~ FFFF no see control word description
2 control word three KG2 0000 ~ FFFF no see control word description
2 control word four KG3 0000 ~ FFFF no see control word description
2 control word five KG4 0000 ~ FFFF no see control word description
3 high-pressure side of the rated current IH 0.2 ~ 15.0 A
4 low side rated current IL 0.2 ~ 15.0 A
5 -speed differential breaking current Isd 3Ie ~ 12Ie A
6 differential starting current Iqd 0.2Ie ~ 2Ie A
7 percentage differential inflection current Izd 0.2 ~ 15.0 A
8 percentage differential braking coefficient Kcd 0.20 ~ 1.00 None
9 second harmonic restraint coefficient Kxb 0.00 ~ 1.00 None
10 cooling fault trip delay 1 Tlq1 0 ~ 9000 S
Cooling fault trip delay 2 Tlq2 0 ~ 9000 S
3 Current section Ⅰ I1 0.2 ~ 100.0 A
4 Current Ⅱ paragraph I2 0.2 ~ 100.0 A
5 Current Ⅲ section I3 0.2 ~ 100.0 A
6 Current section Ⅰ time T1 0.0 ~ 20.00 S
7 Current Ⅱ period of time T2 0.0 ~ 20.00 S
8 Current section Ⅲ time T3 0.0 ~ 20.00 S
9 zero sequence current segment Ⅰ I01 0.2 ~ 100.0 A
10 zero-sequence current Ⅱ segment I02 0.2 ~ 100.0 A
11 zero- sequence current Ⅲ section I03 0.2 ~ 100.0 A
12 zero- sequence current segment Ⅰ T1 time T011 0.0 ~ 20.00 S
13 zero- sequence current segment Ⅰ T2 time T012 0.0 ~ 20.00 S
14 zero-sequence current Ⅱ period T1 time T021 0.0 ~ 20.00 S
15 Ⅱ zero sequence current time period T2 T022 0.0 ~ 20.00 S
16 zero- sequence current section Ⅲ time T03 0.0 ~ 20.00 S
17 gap zero sequence current Ij0 0.2 ~ 100.0 A
18 Ⅰ zero sequence current time gap Tj1 0.0 ~ 20.00 S
19 zero- sequence current gap Ⅱ time Tj2 0.0 ~ 20.00 S
20 zero- sequence voltage U0 1.0 ~ 120.0 V
21 zero- sequence voltage Ⅰ time Tu01 0.0 ~ 20.00 S
22 zero- sequence voltage Ⅱ time Tu02 0.0 ~ 20.00 S
23 low voltage UL 1.0 ~ 100.0 V line voltage
24 Negative sequence overvoltage U2 1.0 ~ 120.0 V
25 overload current Igfh 0.2 ~ 100.0 A
26 overload time Tgfh 0.0 ~ 100.00 S
27 Current Start -cooled Ifl 0.2 ~ 100.0 A
28 air-cooled current start time Tfl 0.0 ~ 100.00 S
29 current lockout regulator Ibs 0.2 ~ 100.0 A
30 current lockout regulator time Tbs 0.0 ~ 100.00 S
31 reclosing time Tch 0.2 ~ 20.00 S
32 current acceleration section Ijs 0.2 ~ 100.00 A
33 current accelerated period of time Tjs 0.0 ~ 5.00 S
34 measuring CT ratio (KA / A) CT 0.001 ~ 10.0 without a current / ( secondary current * 1000 )
35 measuring PT ratio (KV / V) PT 0.001 ~ 10.0 No one voltage / ( secondary voltage * 1000 )
Control word a definition:
Bit is set to 1 meaning set of meanings 0:00
15 CT rated current 1A CT rated current 5A
14 transformer Y / △ -11 wiring wiring adapter to Y/Y-12
13 second harmonic restraint into the second harmonic restraint exit
12 CT CT disconnection disconnection locking differential protection is not locking differential protection , only letters
11 into the cooling cooling fault trip delay fault trip delay exit
Accelerated investment accelerated exit 10
9 reclosing into reclosing exit
8 Switchgear Switchgear coincidence does not coincide
7 Sum Sum self-test to exit into the self-test
Section 6 overcurrent protection by low voltage lockout put Ⅰ Ⅰ quit after overcurrent stage low pressure lockout
5 low voltage lockout overcurrent Ⅱ segment by segment through low- input overcurrent latch exit Ⅱ
4 low-voltage lockout overcurrent Ⅲ paragraph by paragraph into overcurrent Ⅲ exit by low pressure lockout
Section 3 Ⅰ by negative sequence overcurrent overvoltage lockout input overcurrent stage Ⅰ negative sequence overvoltage lockout after exit
2 Ⅱ segment was negative sequence overcurrent overvoltage lockout into segments by the negative sequence overcurrent Ⅱ overvoltage lockout exit
After a negative sequence overcurrent Ⅲ segment input overvoltage lockout Ⅲ section by negative sequence overcurrent overvoltage lockout exit
0 Reserved Reserved
Control word two definitions : Exports programming control word.
Bit is set to 1 meaning set of meanings 0:00
15 zero-sequence segment Ⅱ Ⅱ zero sequence into segments T2 T2 exit
14 zero-sequence segment Ⅱ Ⅱ zero sequence into segments T1 T1 exit
13 Ⅰ period T2 zero sequence into zero-sequence segment Ⅰ T2 exit
12 zero-sequence segments T1 Ⅰ Ⅰ T1 into the zero-sequence segment exit
11 overcurrent direction refers to the direction pointing system transformer overcurrent
10 overcurrent stage overcurrent Ⅲ Ⅲ jump segmented into sub- segments jump exit
9 overcurrent stage Ⅲ Ⅲ segment overcurrent jump jump into the contralateral contralateral exit
8 overcurrent jump into the side section Ⅲ Ⅲ segment overcurrent jump the side exit
7 segment direction overcurrent Ⅱ Ⅱ segment into the direction of exit overcurrent
6 overcurrent input overcurrent Ⅱ Ⅱ segment segment segment jump jump segmented exit
5 overcurrent section Ⅱ Ⅱ segment overcurrent jump jump into the contralateral contralateral exit
4 overcurrent section Ⅱ Ⅱ overcurrent jump into the side of the side of the exit segment jump
3 overcurrent stage overcurrent stage Ⅰ Ⅰ direction into the direction of exit
Section 2 overcurrent Ⅰ Ⅰ jump jump segmented into sub- segments overcurrent exit
Section 1 overcurrent overcurrent stage Ⅰ Ⅰ jump jump into the contralateral contralateral exit
Section 0 overcurrent Ⅰ jump into the side of the side overcurrent stage Ⅰ jump exit
Control word three definitions: export program control word. Bit is set to 1 meaning set of meanings 0:00
15 Reserved Reserved
14 zero-sequence segment Ⅲ jump segmented into sub- zero sequence Ⅲ segment jump exit
13 zero-sequence segment Ⅲ jump into the opposite side of the zero-sequence segment Ⅲ jump contralateral exit
12 zero-sequence jumps into the side of the zero-sequence segment Ⅲ Ⅲ segment jumped the side exit
11 zero-sequence segments Ⅱ period T2 jump into the zero-sequence segments Ⅱ period T2 jump exit
Zero sequence zero-sequence Ⅱ Ⅱ paragraph 10 section T2 T2 jump jump into the opposite side contralateral to exit
9 zero sequence Ⅱ period T2 jump into the side of the zero-sequence Ⅱ period T2 jump the side exit
8 zero-sequence segments Ⅱ period T1 jump into the zero-sequence segments Ⅱ period T1 jump exit
Zero sequence zero-sequence Ⅱ Ⅱ section 7 paragraph T1 T1 jump jump into the contralateral contralateral exit
6 zero sequence Ⅱ period T1 jump into the side of the zero-sequence segments T1 Ⅱ jump the side exit
5 zero-sequence segment Ⅰ T2 jump into sub- zero sequence segment Ⅰ T2 jump segmented exit
4 zero-sequence segment Ⅰ T2 contralateral jump into the zero-sequence segment Ⅰ T2 jump contralateral exit
3 zero-sequence segment Ⅰ T2 jump into the side of the zero-sequence segment Ⅰ T2 jump the side exit
2 zero-sequence segment Ⅰ zero sequence T1 jump segmented into sub- segments Ⅰ T1 jump exit
A zero-sequence segment Ⅰ T1 contralateral jump into the zero-sequence segment Ⅰ T1 jump contralateral exit
0 zero sequence segment Ⅰ T1 jump into the side of the zero-sequence segment Ⅰ T1 jump the side exit
Control word four definitions: export program control word.
Bit is set to 1 meaning set of meanings 0:00
9-15 spare spare
8 gap protection T2 T2 jump jump segmented into sub- gap protection exit
7 jump the gap to protect the contralateral T2 T2 jump into the opposite exit gap protection
6 jump the gap protection T2 T2 side jump into the gap to protect the side exit
5 sub- investment gap protection gap protection T1 T1 jump jump segmented exit
4 gap protection gap protection T1 T1 jump jump into the contralateral contralateral exit
3 gap protection T1 jump into the gap to protect the side of the side exit T1 jump
2 investment gap protection gap protection T2 T2 exit
An investment gap protection gap protection T1 T1 exit
0 fetch current gap protection gap voltage protection take
3.2 , soft list and description of the platen
Corresponding function name plate
Instantaneous differential differential protection feature cast back
Differential differential protection function cast back
Current segment segment Ⅰ Ⅰ current protection cast back
Current Ⅱ Ⅱ segment segment current protection cast back
Current Ⅲ Ⅲ segment segment current protection cast back
Segment zero sequence zero-sequence segment Ⅰ Ⅰ protection cast back
Zero sequence zero-sequence segment Ⅱ Ⅱ segment protection cast back
Zero sequence zero-sequence segment Ⅲ Ⅲ segment protection cast back
Gap protection gap protection cast back
Overload Overload protection cast back
Ventilation flow ventilation feature cast back to start
Latching function regulator regulator overcurrent latch cast back
Heavy gas tripping heavy gas investment return trip
Heavy gas regulator tripping tripping cast back heavy gas regulator
Cooling failure of cooling failure cast back
Pressure relief pressure release cast back
Body light gas light gas tripping tripping body cast back
Light gas regulator tripping tripping cast back light gas regulator
High oil investment return trip tripping high oil