Study On Arc Extinguishing Characteristics Of Circuit Breaker Based On Radiated Electromagnetic Wave

Circuit breakers are one of the most important electrical equipment in a power grid system and serve as a dual task of protection and control.Arc extinguishing characteristics of the circuit breaker performance is the most important characterization,the test methods include electrical life curve method,contact resistance method and SF6 water test.Electrical life curve method can not detect the sudden failure inside the arc chamber.The contact resistance method and the SF6 water test can not realize the live test due to the technical conditions,and only reflect the deterioration of the single parameter of the circuit breaker.Aiming at the shortcomings of the existing methods,the method of detecting the arc-extinguishing characteristic of the circuit breaker based on the radiation electromagnetic wave signal is proposed in this paper,which can be easily and simply applied to the arc-extinguishing characteristic of the live-charged circuit breaker.In this paper,the modular circuit breaker experimental platform was built and the opening and closing test was carried out to study including the fracture voltage,speed,load types and extent of ablation and other factors on the impact of electromagnetic radiation signals.Based on the simulation test,the real test of the circuit breaker was carried out.The difference between the electromagnetic signal radiated by the closing process under the three states of the original state of the circuit breaker,the three short circuit breaking currents and the six short circuit breaking currents was compared.Finally,the radiated electromagnetic wave method was applied to the actual test,and the tests on the characteristics of the are extinguishing were carried out for the circuit breakers with different voltage levels,different types and different breaking times.Research indicates:The higher the fracture voltage,the slower the movement speed,the more serious the contact erosion will make the amplitude of the electromagnetic wave signal increase,the number of signals increases and the duration will be longer.When the circuit breaker breaks the short-circuit current for many times and the arc-extinguishing performance is reduced,there is the burning phenomenon in the interrupter outlet,the outer diameter of the moving arc contact is unevenly distributed after being ablated,and the arc contact is obviously eroded.At the same time,with the increase of the number of short-circuit current ablation,there is an increasing trend in both the peak and the peak number of the interrupter radiating signal in the circuit breaker opening-closing process.The actual test shows that the results of the radiated electromagnetic wave test are consistent with those of many conventional test methods.And in practical application,a case of suspected deterioration of arc extinguishing characteristics of circuit breakers was discovered by radiated electromagnetic wave method.After that,the reliability of the test result was verified by the static loop resistance method.The interrupter was finally disassembled,and ablation was confirmed inside the interrupter.