Fault recording device is a device that can automatically record electrical harmonics and various electrical quantities when the power system is in fault and vibration. It is mainly used to detect the action behavior of relay protection and safety automatic device, understand the change law of various electrical quantities in the system transient process, and check the correctness of power system calculation program and model parameters.

Now the sampling frequency of fault recorder data acquisition system is as high as several hundred times per cycle, which can get very detailed and real electrical waveform and data. These waveforms and data contain a lot of information.

After the fault recording is triggered, the data will be collected and stored according to the preset recording time. These periods are as follows:

Recording time before fault: this part of recording data is mainly used for fault location calculation.

Trigger period: this part of recording data records the early process of fault occurrence, which contains more transient components. This part of data is mainly used for fault location and other electrical calculation after fault.

Post fault period: this period mainly records the situation of the system after the end of the fault. This period of data is mainly the change process.