Transmission power control using variable inductance with feedforward- and feedback-based power controllers

The transmission power is essentially restricted by a line inductance. The authors have previously proposed the transmission power control using a variable inductance which can be realized by variable active passive reactance (VAPAR). The transmission power controlled by this variable inductance with feedforward-based power controller showed quick transient response, although there were slight transient oscillations. This paper, at first, describes a basic theory of the power control method using a variable inductance. Second, the concept of the power control method using variable inductance with a feedforward-based power controller is expressed. Simulations and experiments were carried out using the feedfoward-based power controller to verify the ability of this method. Then, the characteristics of the power control were analyzed for different line impedance by simulations. The results show that the transmission power can be quickly controlled using variable inductance with the feedfoward-based power controller in the case with a small line resistance, while transient oscillation is observed in the transmission power when a line is rather large. Third, a new transmission power control using a variable inductance with a power feedback-based controller is proposed, which can be applied to a power system with large line resistance. The effectiveness of the proposed method was verified by simulations. The transient response of the transmission power can be greatly improved using the proposed method.