The 9681 main transformers High-Voltage side backup protection relay is applicable to the protection of the three-winding main transformer high voltage side backup protection and two winding main transformer high voltage side backup protection, Such protection is generally the concentrated the screen, it can also be installed separated, Fully supported the distributed protection system.
the protection device consists of the completed two or three winding main transformer protection with the 9692,9693 main transformer differential protection device, the 982 main transformer medium-voltage side backup protection measuring and control device, the 9683 main transformers low Voltage side backup protection measuring and control device, the 984 main transformer backup operating gear, the 985 main transformers non-electric quantity protection,
the function of the protection relay
Overcurrent instantaneous trip(trip segmentation), with low voltage lockout, negative sequence voltage lockout.
time delay overcurrent instantaneous trip(all the breakers in the main transformer trip), with low voltage lockout, negative sequence voltage lockout.
The Over-current instantaneous trip and time delay overcurrent instantaneous trip can be chosen, interphase direction selection.
time delay current instantaneous trip (time delay current instantaneous trip, the direction of the time delay the current instantaneous trip, low voltage lockout);
overload alarm.
CT line-break
zero sequences over current(zero sequence overcurrent, Zero sequence voltage lockout、zero sequence trip、Zero sequence direction selection).
Clearance zero sequence protection,
PT no voltage(alarm),
PT line-break(alarm),
busbar grounding (alarm),
pressure anomaly (SF6 Low-pressure alarm),
Measuring and control
busbar voltage :Uab、Ubc、Uca;Ua、Ub、Uc;
measuring current :Ia、 Ib、 Ic、
power:P、Q、cosФ;
frequency:f;
Auxiliary function
control circuit break,
Manual closing and switch in
remote closing and switch in.
Fault recorder
communication mode
485 communication
Ethernet communication
Optical fiber communication.
Protective action principle
① time delay current instantaneous trip protection
1.RLP1 time delay current instantaneous trip protection-in service
2.Protective current IA(IB)IC anyone sampling value≧ the fixed value of the time delay current instantaneous trip protection(Idz3)
3.Time of the current≧time delay current instantaneous trip protection tzd3
Protect immediate output C7/C8、C9/C10、C11/C12, at the same time the 同时驱动accident signal relay drive C1/C3(return after 10s ), Panel accident light
② I—II segment Combined voltage blocking over current protection
The device is set with a three-segment composite voltage blocking over current protection. Three-section protection and time setting value can be set separately, According to the actual situation, we can choose the compound voltage or the compound voltage to start over current protection. In order to prevent the decrease of the PT line-break or the PT voltage, the protection will automatically withdraw from the negative sequence voltage and low voltage when the alarm signal occurs.
(1).Zero sequence current instantaneous trip protection (Delayed time trip C15/C16)
(2).Zero sequence time delay current instantaneous trip (Delayed jump trip the sideC7/C8)
(3).Zero-Sequence definite time over-current (Delayed trip, trip to the side, the side of the trip C7/C8、C9/C10、C11/C12)
(4).Low voltage blocking over current; (Need to put "over current" protection at the same time,and no PT line-break, no PT loss voltage)
the low voltage judge by Uca Line voltage, the current is greater than the set value at a certain phase, Uca line voltage is less than the set value(General low voltage set value is 70V), then protection will be able to move,It is mainly used for the discrimination of voltage symmetrical short circuit, and the negative sequence voltage;
(5).Negative sequence voltage lockout over-current; (need and put into "over current protection and a continuous line of PT without losing pressure) negative sequence voltage is mainly used for voltage asymmetric short circuit, in a phase, current protection is greater than the set value, the negative sequence voltage greater than a set value (usually negative sequence voltage setting for 7V) protection will be an act.
Description: at the same time put into the "over current, low voltage blocking over current, negative sequence voltage blocking off flow", can reduce the current transient error, and can guarantee the voltage in the symmetrical short circuit and asymmetric short circuit protection action.
③ Clearance zero sequence overcurrent protection
1.RLP12 Clearance zero sequence-in service
2.Gap zero-sequence current Io sampling value ≧Clearance over current fixed value(Ijdz1)
3.Time of Zero sequences current ≧Clearance overcurrent delay tjzd1
Protect immediate exit C7/C8、C9/C10、C11/C12,Simultaneous drive accident signal relay C1/C3(Return after 10s), Panel accident light.
④ Overload
1.RLP9 Over load-in service;
2.Protection current IA(IB)IC anyone sampling value≧ Overload fixed value(Idz4)
3.Time of current≧Overload delay tzd4
Protection immediately driving alarm signal relay C2/C3(return after 10s). Panel warning light.
Description: if overload needs on-load voltage regulation (the low backup is open the fan overload, the same as following), you need to
Description: overload if you need to lock the load voltage adjustment (low backup is overload open the fan, with the next), you need to
1.RLP17 Overload alarm -in service
2.RLP18 Overload on- load voltage regulation-in service
3.Protection current IA(IB)IC Any phase sampling value≧ Overload fixed value(Idz4)
4.Time of current≧Overload delay tzd4
Protect immediate exitC17/C18,Simultaneous drive accident signal relay C1/C3(Return after 10s). The panel warning light is on.
⑤ Zero sequence overcurrent
1.RLP8 Zero sequence overcurrent-in service
2.Zero sequence current 3Io sampling value≧ Zero sequence overcurrent fixed value(Iodz)
3.After a period of delay(Exit C15/C16)、The two section(export C7/C8、C9/C10、C11/C12)、 three-section (Exit C7/C8、C9/C10、C11/C12)
Protection immediate exit, while driving accident signal relay C1/C3(Return after 10s). Panel accident light.
⑥ Zero sequence over-voltage
1.RLP11 Zero sequence over-voltage-in service
2.Zero sequence voltage 3Uo sampling value ≧ Zero sequence overvoltage(Uodz2)
3.After delay T0zd4
Protect immediate exit C7/C8、C9/C10、C11/C12,Simultaneous drive accident signal relay C1/C3(Return after 10s). Panel accident light
⑦ control circuit break
1.RLP7 control circuit break-in service
2.Protection device control circuit break time≧Control loop delay(Tdz3);
Protection immediately driving alarm signal relay C2/C3(Return after 10s). Panel warning light
Description: the control loop is broken.:
If the switch is in the position of the closing status, the information of the control loop is broken, the trip coil circuit is disconnected.;
If the switch in a state of breaking, send out the "control loop break" information, then the closing coil circuit disconnect
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