Research On EMC Principle And Test Of Intelligent Circuit Breaker Controller

Intelligent circuit breaker controller worked in the substation which electromagneticenvironment was extremely bad, and was subject to a variety of electromagnetic interferencesin the work process, its EMC level directly affected safety and reliability of power system.Additionally, the controller was a weak electrical equipment which was based onmicroelectronics and computer technology, including its operating mechanism was electronicactuator, compared with the relay control of traditional breaker, its immunity level weakenedsignificantly.Therefore, the research on EMC of intelligent circuit breaker controller was extremelyimportant and indispensable. In the thesis, taking the EMC design and research of synchronouscircuit breaker controller that laboratory researched and developed as an example,and then thegeneral EMC design and research criterion of general intelligent circuit breaker controllerwere obtained.In order to improve anti-electromagnetic interference ability of synchronouscircuit breaker controller, main EMI sources in substation were studied, such as generationmechanism of electrical fast transient burst, lightning surge, electrostatic discharge anddamped oscillatory, and the corresponding immunity test standards. And time domain andfrequency domain characteristics of standard interference waveforms were analyzed. Theelectromagnetic interference waves which can simulate standard test waveforms were set upby using circuit theory. Then the coupling form and function form of electromagneticinterference were introduced. Next, EMC of each port was studied and analyzed, EMC designand analysis of power port, AC input port, switch input/output port, permanent magneticactuator coil drive port, transmission route of interference in these ports, and simulation andanalysis of several anti-interference measures were focused on. For coil drive port, modelingand simulation of main drive circuit turn-off surge overvoltage based on Saber was alsomainly studied, including modeling of switching devices, extraction of circuit parasiticparameters, optimization of snubber circuit structure and parameters. Finally, diagnostic EMCimmunity test of the synchronous circuit breaker controller was conducted, mainly includingelectrical fast transient burst immunity, lightning surge immunity, the damped oscillatoryimmunity and electrostatic discharge immunity tests. A detailed description of the testingprocess, the test case analysis, and corresponding solutions of the problems encountered weregiven.The device has passed through the most severe level of immunity test, and has alsosuccessfully passed the EMC national test.Thus, EMI control technology and related theoretical analysis in the hardware platformdesign process of intelligent circuit breaker controller were proved correct. It had a certain practicality and feasibility, and also had a certain reference value to other power systemintelligent electronic equipments.