Simulation of Line-Commutated Rectifier Systems Using Fixed Time-Step without Zero-Crossing Events

Line-commutated rectifiers (LCRs) are widely used in many industrial applications and electronic loads. For analysis and simulation of power systems that include many switching converters, numerically efficient and accurate models of rectifiers are needed. The detailed switching models of LCRs in traditional electromagnetic transient (EMT) simulation programs (either state-variable-based or EMTP-type) require special handling of switching events (i.e., interpolation and/or use of small time-steps for zero crossing detection), which results in increased computational complexity. This paper presents the recently developed generalized parametric average-value model (GPAVM) of LCRs that is capable of predicting the ac harmonics of interest with good accuracy while using fairly large fixed time-steps without the need for handling the zero-crossing events. This feature represents an advantage over the established methods and may be utilized for more efficient simulation of power systems with many rectifier loads.