Efficient Simulation of Variable-Speed Diesel-Engine Generators Using Constant-Parameter Voltage-Behind-Reactance Formulation

Diesel-engine generators can operate with variable speed to enhance their efficiency over a wide range of loading conditions. Constant-parameter voltage-behind-reactance (CPVBR) models have been developed for efficient simulation of three-phase wound-field synchronous generators (WFSGs). The CPVBR models use fixed branches for interfacing (without any incompatibility, e.g., the need for snubbers, etc.) and are not required to update their interfacing circuit in every time step of the simulation. This paper presents the application of the CPVBR model of a WFSG for efficient simulation of a variable-frequency/speed diesel-engine generator-rectifier system. Simulation studies are carried out in MATLAB using PLECS toolbox to verify the computational performance of the CPVBR model. It is demonstrated that the CPVBR model achieves superior computational performance (without compromising the accuracy) compared to the built-in models of the toolbox, i.e., qd0, stator VBR, and full VBR models.