专业生产发电机保护测控装置*代理

深圳南网国瑞科技有限公司

3.10 stator overvoltage protection
For generator, in particular to a hydro generator, after load rejection due to the speed control of speed control system can not keep up, is easy to appear the stator voltage exceeds the allowed range of over voltage phenomena; at this point to be equipped with over voltage protection, protection from the generator terminal voltage when any phase of more than setting value by setting the delay action to stop.
3.11 stator ground protection
Generator stator grounding protection can for the generator neutral point ungrounded or via arc suppression coil grounding grounding, protection from the generator end opening of the delta winding voltage when open delta windings voltage greater than setting value by setting the exit delay.
1.3 function configurationFunction configuration of SAI3880D digital generator differential protection deviceDifferential quick break, ratio brake differential, CT disconnection locking differential, CT disconnection alarm, stator overvoltage protection, stator ground fault protection, overload alarm, anti time overcurrent protectionFunction configuration of backup protection device for SAI3881D digital generatorTransverse differential protection, loss of excitation protection, rotor one point grounding protection, rotor two points grounding protection composite voltage over current protection, inverse time negative sequence overcurrent protection, Pt disconnection alarm, non electricity protection (generator water shutoff, and the generator thermal, generator excitation accident, main steam valve closed),

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.
2.2 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