Dynamical and Voltage Profile Stability of Inverter-Connected Distributed Power Generation

We present a systematic stability analysis of inverter-connected distributed generation. Our approach is to replace simulations with much faster and more informative analysis using transfer functions. The transfer functions characterize the dynamics of the interconnected feedback loops in the system. The methodology is applicable to different types of inverters, including droop inverters. It also may be applied to distribution systems with arbitrary topology. The analysis allows evaluation of system stability and performance, subject to frequency, load, and power set-point disturbances. By means of two examples we demonstrate how the proposed approach can help in analysis and engineering of the distribution systems with acceptable frequency and voltage profile responses to both distributed generation power and grid frequency disturbances.