自动发电机保护测控装置 南瑞

深圳南网国瑞科技有限公司

Three、Software function deion
3.1. differential quick break protection
When any phase difference current is greater than the value of the differential speed, the protection action is stopped. Fast removal of generators in the case of a serious fault in the area of the generator. Differential speed determine the value should be able to avoid the external fault of the maximum unbalanced current, and taking into account the current transformer saturation factor, generally take 3 to 8 times the rated current

3.2.Ratio differential protection
Using the conventional ratio differential principle, the equations of motion are as follows:
Id > Icd （Ir Ir0）
Id - Icd > Kcd ·(Ir- Ir0) (Ir ≥ Ir0)
At the same time to meet the above two equations, the ratio of the differential element action. Among them, Id for the differential current, Ir for the braking current, Kcd for
Ratio braking coefficient, Icd is the threshold value of the differential current, and Ir0 is the turning point of the current value.

2.3.2 medium strengthUnder normal test conditions, the device can withstand the frequency of 50Hz, voltage 2000V lasted 1 minutes of power frequency voltage withstand test without breakdown flashover and component damage. During the test, the other circuit is connected to the ground with the other circuit when the voltage is applied.
2.3.3 impulse voltageIn the normal test atmospheric conditions, device power input circuit, the AC input circuit, output contact circuit and loop between, can withstand the 50s of the standard lightning wave short-time impulse voltage test, open test voltage 5kV.
2.3.4 resistance to damp heat resistance
The device can withstand the damp heat test specified in the twenty-first chapter of the GB7261. The highest temperature test + 40 DEG C, maximum relative humidity of 95%, the test time for 48 hours, each cycle lasted 24 hours of cyclic damp heat test, at the end of the test within 2 hours before according to the requirement 2.3.1, measure the circuits between the conductive circuit foreign Lufei charged metal part and the shell, electrical contact between the insulation resistance is not less than 1.5m ohm, medium compressive strength of not less than 75% of the 2.3.2 provisions of the dielectric strength test voltage amplitude.
2.4 electromagnetic compatibility
2.4.1 electrostatic discharge reactance
Through the GB/T 17626.21998 standard, electrostatic discharge immunity test IV.
2.4.2 radio frequency electromagnetic field radiated immunity
Through the GB/T 17626.31998 standard, RF electromagnetic field immunity test level 3.
2.4.3 electric fast transient pulse group immunity
GB/T 1998 - 17626.4 standard, electrical fast transient pulse group immunity test.
2.4.4 surge (impact) immunity
Through the GB/T 1999 - 17626.5 standard, surge (impact) immunity test 3.
Conduction disturbance degree of 2.4.5 RF field induction
Through the GB/T 17626.61998 standard, RF induction level 3 test conducted
2.4.6 power frequency magnetic field immunity
Through the GB/T 1998 - 17626.8 standard, the power frequency magnetic field immunity 5 level test
2.4.7 pulse magnetic field immunity
Through the GB/T 1998 - 17626.9 standard, the pulse magnetic field immunity 5 level test.
2.4.8 damped oscillatory magnetic field immunity
Through the GB/T 1998 - 17626.10 standard, damped oscillatory magnetic field immunity test 5 levels of test.
2.4.9 oscillation wave immunity
Through the GB/T 1998 - 4 standard, 17626.12 - level oscillation wave immunity test.
AC measurement
A group of three-phase current, three-phase voltage and zero sequence voltage, power, frequency, power, power factor
Switch input
11 way switch input, can be the whole set of non electric power for "trip" or "alarm", the first 4 non electricity can be arbitrarily set trip exit
Switch output
8 way switch contact output, the 4 switch jump closing control
control loop
Jump control circuit, circuit breaker hand jump, hand closing operation and hop position indication

2.2.4 precision of various components
Current component: <5%
Voltage components: <5%
Time element: 0s-1s, the error is not more than 40ms;
1s above, the error is not more than < + 2.5%;
Frequency deviation: <0.02Hz
2.2.5 the entire set of action time (including the inherent time of the relay)
Time of motion of a fast moving segment:
1.2 times the value of the entire set of measurement, not more than 50ms
2.2.6 transient transcendence
No more than 5%
2.2.7 og measurement loop accuracy
Measurement and control device for installing special measurement sub module:
Current, voltage: 0.2
Power and electric degree: 0.5
2.3 insulation performance
2.3.1 insulation resistance
Device for charged and uncharged part and a casing and electrical contact of the circuit between the open circuit voltage of 500V megohm meter measuring the insulation resistance value, normal test atmospheric conditions, the circuits of each class of insulation resistance should not be less than 100m ohm.
2.3.2 medium strengthUnder normal test conditions, the device can withstand the frequency of 50Hz, voltage 2000V lasted 1 minutes of power frequency voltage withstand test without breakdown flashover and component damage. During the test, the other circuit is connected to the ground with the other circuit when the voltage is applied.
It is proposed that the turning point in the component current Ir0 is set to 1 times the rated current of the high voltage side to ensure that the turn to turn short circuit in the braking current is less than the rated current Ie Ir, there is no braking effect.
Differential current threshold criterion should not be too small, it is recommended to take Icd = (0.3 ~ 0.5) Ie.
The setting of the ratio braking coefficient can be carried out according to the following formula:
Kcd = Kk (Ktx / Fwc + Fph)
Among them, Kk is the reliable coefficient, take 1.3 ~ 1.5
Ktx for the same type coefficient, take 1
Fwc for the current transformer to allow the error, take 0.1
The Fph for the current caused by current transformer unbalanced relative error is 0.05.
Ratio braking coefficient Kcd recommended range of 0.3 to 0.7.Id ＝∣