Angle Control Using Corona Discharge Considering Voltage Range Limitations

A corona discharge is a type of self-sustaining discharge, which is often observed between pin-to-plate electrodes under high-voltage application. Force generation using the corona discharge has no moving parts and is robust; therefore it can be used as a new actuator. However, the relationship between the input voltage and output force caused by the corona discharge is highly nonlinear, so it is essential to deal with this issue through control. In particular, it is important to consider the two types of limitations induced by the corona discharge. First, the corona discharge has a lower voltage limit at which the discharge is initiated, thus without the consideration of the corona inception voltage, the response speed deteriorates, and the overshoot increases. Second, excessive applied voltage causes spark discharge, which causes safety problems. Therefore, this paper proposes voltage reference generation and an angle control method based on differential mode voltage that considers the aforementioned voltage range limitations. Simulations confirm that the proposed method improves the response speed by 13.2% and suppresses the overshoot by 28.0% when torque disturbances are added while the applied voltage fit within the desired range.