Test equipment: CYGI Shenrui PRS-753S optical fiber longitudinal complete set of protection device.
Use the device: Relay-STAR-1600 Relay Protection Test System.
: Relay-STAR-1600 Relay Protection Test System.
Test principle: Suppose that the M side is the power transmission end and the N side is the power receiving end. Under normal conditions or when an out-of-area fault occurs, the amplitude of the currents on both sides of m and n are the same and the direction is opposite. According to the principle of differential current (the differential current is the sum of the current vectors on the local side and the opposite side), the difference current is zero. When a fault occurs in the area, the current on the N side is reversed, and the current inflow on both sides of M and N is equal in amplitude and in the same direction, and the differential current generated is twice the fault current of each phase. 
Schematic diagram of the composition of the optical fiber current differential protection system.
According to the protection requirements, when the amplitude of the differential current is less than the setting value of 0When 95 times, the protection is reliable and does not operate; When the differential current value is greater than or equal to the setting value of 1At 05 times, the protection is reliable and the action time is less than 100ms.
Note:In the actual test, the pigtail of the protection device (the optical fiber connected to the opposite side of the protection) is usually self-looped, and the local side and the opposite side identification code are set to the same. At this time, the fault current value sent by the opposite side (actually the local side) received by the protection device through the optical fiber is added to the fault current value of the local side to be the test differential current value. From this, it can be estimated that the actual value of the experimental current is one-half of the value of the differential current generated.
Protective device setting value:
Variable starting current fixed value: 02a
The differential action current is fixed at 12a
Test Method:
1. The protective device is set
Platen setting: overhaul pressure plate input, longitudinal differential protection input, A, B, C trip outlet pressure plate exit.
Control word setting: Set the value setting - longitudinal differential protection to 1, and set the other control words to 0.
2. Wiring
Wiring schematic.
Disconnect the connection scribing on the IA, IB, IC, IN terminal strip to disconnect the protection device from the line.
Connect the IA, IB, IC, and IN output ports of the tester to the corresponding terminal strip protection device side.
Connect the tester UA, UB, UC, and UN to the corresponding terminal strip.
The switch input of the tester + km terminal access device positive power terminal port.
The switch of the tester is input into the tripping coil terminal port of the A terminal access device (the tripping outlet of the pressure plate is selected this time).
Relay Star-1600 wiring diagram.
Voltage and current wiring
Switching amount + km wiring.
Trip coil wiring.
Before the fiber self-looping.
After the self-loop. Experimental manipulation
1. Verify 0Under the setting value of 95 times, the differential protection is reliable and does not operate. (Verify phase A separately, other phases can refer to this setting).
According to the differential action value 12a calculates that the experimental value of differential current is 12*0.95=1.14A, the experimental current is 057a。
1) In the "Status Sequence" menu, add two statuses: before failure and before failure.
ua=ub=uc=57.734v
ia=ib=ic=0a
Both voltage and current are in positive order.
Trigger mode: 15s at a time
Positive normal label parameter settings.
ua=ub=uc=57.734v
ia=0.57a
Both voltage and current are in positive order.
Trigger mode: 01s
Fault state label parameter setting.
2) Increase
Once you're set up, click Run. The relay protection test system outputs a duration of 15s according to the normal state set value, and the device automatically switches to the next state after 15s, and the relay Star-1600 outputs a duration of 0 according to the fault state set value1s。
Results: No trip signal was collected by the tester.
2. Verification 1Under 05 times the setting value, the differential protection is reliable and does not operate. (Verify phase A separately, other phases can refer to this setting).
According to the differential action value 12a calculates that the experimental value of the differential current is 12*1.05=1.26A, the experimental current is 063a。
1) In the "Status Sequence" menu, add two statuses: before failure and before failure.
ua=ub=uc=57.734v
ia=ib=ic=0a
Both voltage and current are in positive order.
Trigger mode: 15s at a time
Fault state label parameter setting.
Positive normal label parameter settings.
ua=ub=uc=57.734v
ia=0.63a
Both voltage and current are in positive order.
Trigger mode: 01s
2) Increase
Once you're set up, click Run. The relay protection test system outputs a duration of 15s according to the normal state set value, and the device automatically switches to the next state after 15s, and the relay Star-1600 outputs a duration of 0 according to the fault state set value1s。
Experimental results: the tester receives the tripping signal sent by the protection (the tripping mode of this experiment is three-phase tripping), and the action time of the tester switching input A port is 32ms.
According to the experimental requirements, the setting value of 12a: The protection performance under differential current meets the requirements of the regulations.
0.95 times the differential current protection is reliable and does not operate, 105 times the differential current under the protection of reliable action, the action time of 32ms to meet the requirements of quick breaking.