The Investigation Of Intelligentized Protector In Three Phase Electromotor

The protector of electromotor have used heat relay for a long time, but heat relay not only has a dead area in the light over-loading area, but also can't protect open phase under so much circumstances. The operation stability of routine electronic protector has been improved in essence, especially for the improvement of our electronic protector. More and more users begin to use electronic heat relay to replace routine double sheet metal heat relay which drove the machine through radiation and diatortion. But routine electronic protector can't realize the protection for counter time limit, which is matching with the graph of heat over-loading protect. It can only realize "single point protection" and can't protect the failure happened duringstart-up.According to the working characteristic of electromotor, this paper gives deeper investigation to protector of three phase electromotor, applying knowledge of VLSI design and singlechip control. Using the powerful singlechip technology, completing the hardware design of the intelligentized protector and working out the whole protective program. At last, realizing several protective functions, such as over voltage, lack of voltage and over load, and making up many disadvantages of routine protector.This kind of product can bring benefit to control system of switchboard owing to the perfect function and high reliability. It can bring not only huge social benefit, but also considerable economic benefit.