产品规格：
产品数量：
包装说明：
关 键 词：自动发电机保护测控装置
行 业：电气 电气成套设备 变电站
发布时间：2020-10-31
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 ＝∣
2.3.2 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.
2.5 mechanical properties
2.5.1 vibration
The device can withstand the vibration endurance test of the I level of 16.3 in the GB7261.
2.5.2 impact
The device can withstand the impact endurance test of the I level of 17.5 in the GB7261.
2.5.3 collision
The device can withstand the impact endurance test of the GB7261 level of I in the eighteenth chapter.
2.6 environmental conditions
A) ambient temperature: Work: -40 C ~ 85.
Storage: 25 degrees to +70 degrees Celsius, in the limit value does not apply the amount of incentive, the device does not appear irreversible change
After the temperature is restored, the device should be able to work properly.
Relative humidity: the maximum monthly average relative humidity of 90%, while the average monthly average of.
The lowest temperature is 25 DEG C and no condensation surface. When the maximum temperature of +40 degrees Celsius, the average maximum relative humidity
Degree no more than 50%.
(c) atmospheric pressure: 86 to 106kPa (relative altitude below 2km)
1)under the time limit: when the three-phase current is greater than the lower limit of the value of any phase, but not meet the anti time limit start value, press the lower limit delay action on the alarm signal;
2) inverse time: when the three-phase current any phase current is larger than the inverse time starting value, according to the inverse time lag action equation I2-1 t is greater than or equal to K acts, type: I for the generator current standard? Value, K - generator stator winding allows thermal time constant.
3) the upper bound limit: when the three-phase current is greater than the upper limit value, the time limit is delayed by the time limit.
3.8 transverse differential protection
Generator transverse differential protection is usually used for the reaction of generator stator winding inter turn short circuit and a parallel windings open welding, protection from the generator neutral point between two branch imbalance fundamental current, but current is greater than fixed value setting delay action on the alarm or trip.
