Research on DC interrupting and current limiting technology of aviation circuit breakers

With the increase of power supply capacity of aerospace high-voltage DC distribution system, higher requirements are put forward for the breaking capacity and current limiting capacity of aviation circuit breakers. By analyzing the research results around the world, it is believed that the aviation circuit breaker using sealed gas combined with arc blowing magnetic field is an ideal solution to meet the special environmental requirements of aerospace. A test platform has been set up to test and study the arc voltage, current, and arc ignition time under different gas medium pressures and different magnetic field strength, and to analyze the effects of gas pressure and magnetic field strength on the DC circuit breaker's interrupting performance, which provides an important reference for engineering application. Current development of short-circuit current limiting technology was analysed and a PTC (positive temperature coefficient) thermistor-based current limiting device topology was proposed, the current limiting device combined with an aviation circuit breaker which utilized sealed gas and arc blowing magnetic field extinguishing technology was tested. The testing result showed that the designed device can limit the short-circuit current quickly and effectively, and the PTC thermistor has self recovery property which proved a good application prospect.