Here we are going to do some research work about the application of BP neural network in intelligent fault diagnosis of pumping unit.

This paper discusses new trolley safety control system with PLC based on the original relay control system to act as fault diagnosis and protection control.

In recent years,the expert system applied for fault diagnosis and restoration of power systems has focused attention of many authers.

By using the expert s special knowledge at this field, the expert system avoids some of the common program s flaw, such as the the maths model s too complicated, data computing amount too heavy, computing time too long and too many load conversion restrict objects during fault judgement, fault separation, and nonfault region s power supply recovery.

It is shown the principle of fault judgment for control circuit and the transmission protocol of CAN bus.

Strictly carry out the system of operating people who hold certificate to take up posts, the maintenance technician of refrigeration equipment will be careful in fault judgment, accomplish fault judgment surely , otherwise it will arise larger accident easily.

And summarys the application of gas analysis technique online fault judgment of SF6 equipments.

We will introduce the way of judged malfunction(error) according to the state of CPS and Modem.