Design of Permanent Magnet Solenoid Valve for Electric Vehicle AVH

The solenoid valve for traction control valve (TCV) responsible for the automatic vehicle hold (AVH) function of electric vehicles require a continuous supply of power to the magnetic coil in order to operate. When power is continuously supplied, heat is generated because of the resistance of the magnetic coil, which leads to deterioration of the periphery of the solenoid valve and deteriorates durability. To prevent this, when power is applied to the solenoid valve for TCV for more than a certain period of time, the power supply is automatically turned off and the AVH function is controlled to be performed by the electronic parking brake (EPB). In this study, we designed, manufactured, and verified the permanent magnet solenoid valve of TCV for AVH that can minimize unnecessary power consumption of electric vehicle batteries. For the design of the permanent magnet solenoid valve, the location, polarity direction and specifications of the permanent magnet within the solenoid valve were studied through finite element analysis. In order to check whether the braking function by the permanent magnet is maintained even when the current is cut off at AVH’s TCV solenoid valve, electronic control unit (ECU) and electronic stability control (ESC) were manufactured and evaluated for actual vehicle testing. Therefore, it was possible to manufacture a permanent magnet solenoid valve that minimizes unnecessary power consumption of the battery because it does not require power supply even when the car is stopped for a long time in the AVH function of the electric vehicle.