Arc reignition is an important factor affecting the electrical performance of high-voltage DC relay. The magnetic blowing of the rectangular permanent magnet is the main method for extinguishing arc in high-voltage DC relay. To investigate the influence of permanent magnet magnetic field distribution on arc reignition characteristic

the equivalent magnetic charge method is used to simulate and analyze the magnetic field of the permanent magnet

and the magnetic field distribution law of the permanent magnet is obtained. A magnetohydrodynamic arc model is established

and the dynamic process of arc reignition is simulated and analyzed based on the magnetic field distribution of the permanent magnet. The results show that the reason for arc reignition is that the permanent magnet exhibits a non-uniform magnetic field distribution with high magnetic induction intensity in the contact area and attenuation along the periphery

resulting in the accumulation of high-temperature gas between the arc gap and bearing high electric field strength. To improve magnetic field distribution and suppress reignition

three special shaped permanent magnets such as double rectangle

2/3 semi-circular ring and double L-shaped are designed

and their effects on arc reignition are compared and analyzed with rectangular permanent magnet

and experimental verification is conducted. The results show that the improved permanent magnets generate a "dumbbell shaped" magnetic field distribution that increases along the direction of arc motion

which has good inhibitory effect on arc reignition

among which the 2/3 semi-circular ring permanent magnet not only suppresses arc reignition

significantly reduces arc duration

but also saves the material.