PARALLEL RESONANT CONVERTER AS A CIRCUIT SIMULATION PRIMITIVE

The paper presents a SPICE macromodel for a generic parallel resonant converter circuit. The model is derived from the averaged time-invaria nt state-space equations obtained from a Fourier transform. The condit ions are derived under which all but the fundamental harmonic may be d iscarded, and the model developed based solely on the fundamental Four ier component. The single macromodel developed has a wide range of val idity, allowing DC, AC and transient analyses to be carried out using the entire converter as a circuit primitive. Thus, such a converter ma y be incorporated (alongside its control circuitry), as a primitive, i nto an entire system. Example analyses show a parallel resonant circui t, embedded in a feedback loop, becoming unstable when the load underg oes a step change. A similar set of analyses, carried out at component level, yield identical results, but require runtimes greater by a fac tor of between 192 and 6600. Finally, the 'stability region' of the ci rcuit, characterised by the load resistance, is calculated. This kind of information is extremely useful to the designer, and not usually ea sily obtained.