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 =∣
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.
Two technical parameter
2.1 Rated parameters
2.1.1Rated DC voltage: 220V or 110V (order indicated)
2.1.2 Rated AC data:
a) Phase voltage V
2.2 Main technical performance
Precise working range of 2.2.1 sampling circuit (10% error)
Voltage: 0.4 V ~ 120V
Current: 0.08In20In
2.2.2 contact capacity
Signal circuit contact current carrying capacity 400VA
Signal circuit contact fault arc capacity 60VA
2.2.3 tripping current
Breaker trip current 0.5A~4A (order indication)
The circuit breaker closing current 0.5A~4A (the order stated)
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
1)the maximum phase current of a side is less than 20% of the rated current, it is not sentenced to the side;
2)2) the maximum value of the phase current is greater than 120% of the rated current of the side;
3)3) served as the start of one side of the current than before the start of the increase.In the case of the above three conditions are not satisfied, such as one side at the same time meet the following conditions, then sentenced to CT break:
1)only one phase current is zero;
2) the remaining two phase currents are equal before starting the current.
3.3.2 differential current limit alarmIf the difference is greater than 15% of the rated current, after more than 10s discriminant, issued a warning **. Differential current limit, but not locked differential protection. The function and the monitoring function of the AC sampling circuit of the protection device
3.4 loss of magnetic protection
Generator loss of excitation protection for generator excitation current abnormal decrease or disappear completely lost magnetic fault protection, by the generator stator impedance as the main criterion, combined with low voltage and generator excitation system low voltage as auxiliary criterion, and have TV disconnection locking function, TV break send alarm **.
Its action logic is as follows:
-/gjigcb/-
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