The Electrical Life Test For High-voltage DC Relays And The Improvement Research On The Contact Simulation Test Device

High-Voltage DC relays were widely used in the aerospace field and their workingreliability were of great concern. The key technologies involved in the defense sector andwere strong confidentiality. The structure analysis and experimental research onHigh-Voltage DC relays were still lacking at home and abroad. Contact simulation testdevice which was able to achieve real-time multi-channel synchronous collection andstorage did not exist in terms of simulation test. Therefore, research on the key factors ofthe electrical life of High-Voltage DC relays and improvement of contact simulation devicewere important.In order to study the key parameters of High-Voltage DC relays, GX11, HFE18,AEV18012, AEB310012, LEV200and G18/G50relays were anatomized. Combined withrelevant technical data sheet, from the perspective of rated switching condition, contactstructure, contact material, magnetic blowing, gas pressure, atmosphere and the diameter ofcontact, the sample’s structure and design principles could be compared with the parametersand analyzed with the theory. Then the key parameters which affected the electrical life ofHigh-Voltage DC relays would be researched out.G50and GXX relays were put as the research object to conduct electrical life test.Analysis of the test results showed the following three points. RC parallel circuit couldeffectively absorb breaking arc energy, reduce circuit peak voltage, thereby reduce arcerosion on the contacts and extend the electrical life of the relay contacts. Driven arcmagnetic field contributed to fast moving of arc, reducing arc gathering, lengthening arc,thereby accelerating arc extinguish， reducing arc erosion of the contact and was conduciveto the improvement of the electrical life of relays. GXX relays could complete the requirednumber of operations without failure under DC5000V/20A and DC5000V/30A withresistive loads.Following improvement were made on the contact simulation test device. On the onehand, a laser displacement sensor was added on the basis of the original analog device.Then the test function of displacement and speed of moving contact could be achieved. By simultaneously improving the original LabVIEW program, real-time collecting and storingthe parameters of voltage, current, displacement of moving contact, speed of movingcontact and contact pressure could be achieved with the contact simulation device. On theother hand, the measuring system of contact surface was designed. The system consisted ofcontact surface imaging system and image analysis system. It could record the changing ofcontact surface contour, calculation of the maximum height of the convexities and theshortest distance between two surfaces, the position of the plane of the corresponding pointin one direction in the whole process. So research on the formation process of contactmoving welding would be of great concern.