Modeling and analysis of several classes of self-oscillating inverters: Part I- State-plane representations

An overview is provided concerning the analysis of a selfoscillating dc-to-square-wave transistor parallel inverter. The inverter is characterized by an equivalent nonlinear network consisting of a voltage-controlled resistor in parallel with a square-loop saturable reactor and a linear capacitor. Piecewise-linear techniques in conjunction with state-plane interpretations are employed to describe in detail the behavior of the inverter including: the complex switching interactions of semiconductor devices and magnetics, the stability nature of limit cycles, conditions for oscillation, and starting characteristics. The model provides significant insights into the inverter design and is verified experimentally.