Realization of negative inductance using variable active-passive reactance (VAPAR)

The concept of the variable active-passive reactance (VAPAR) has been proposed previously. VAPAR consists of an inverter and a few passive elements with a control system, which behaves like a two-terminal reactive element, and the produced active reactance works as a passive reactive component, including in transient state. The main purpose of this paper is to analyze the characteristics of negative inductance and to show how to produce negative inductance by VAPAR. First, the principle and realization of VAPAR and complete two-terminal VAPAR (CTT-VAPAR) are explained. Second, the characteristics of negative inductance are analyzed from the point of view of frequency characteristics of impedance and transient response, using capacitance as a reference. Finally, through simulations and experiments, it is verified that VAPAR can generate negative inductance, and it is demonstrated that the actual inductance is cancelled.