| Abstract |
Effective features from various modeling methods are complemented with analog simulation, series expansion practices and heuristic guidelines to get a systematic and versatile method to derive accurate and efficient Circuit Oriented Large Signal Average Models (COLSAMs) that approximate the slow dynamics manifold of the relevant state variables for PWM dc to dc and three-phase to dc power converters. These COLSAMs can cover both CCM and DCM operation and they are much cheaper, computation wise, than switching models. From the converter’s operating waveforms and topological stages this method leads primarily to simple and effective input-output oriented models that represent transfer as well as loading characteristics of the converter. Since these models are time invariant and continuous they can be linearized at an operating point to obtain small-signal models that approximate the dynamics of the original PWM system around an orbit. The models are primarily intended for software circuit simulators to take advantage of intrinsic features such as transient response, linearization, etc. without changing simulation environment, but many mathematics simulator can be used with the set of equations obtained by applying Kirchoff’s laws to the COLSAMs. The latter also provide physical insight to help with power stage and control design. A new average model to cover both CCM and DCM operation for the ZVS Full-Bridge PWM converter was developed and its high accuracy is verified with simulations from a switching behavioral model for several component values. |
