Comparison between operating modes of distributed generation on voltage profile and stability of distribution systems

This paper presents a detailed comparison between the effects of operating modes and penetration level of distributed generation (DG) on the steady-state voltage profile and stability of electrical distribution systems. The two operation modes of DG, PQ (constant power mode) and PV (voltage control mode) are studied on the IEEE 33-bus radial distribution system. Penetration level and location of the DG within the system are adjusted to maintain the voltage for all buses within ±5%. The maximum loading point (MLP) and total power loss of the distribution system are registered for every case study. Simulation results show that the operation of DG system in the PV mode of operation displays better performance in achieving greater MLP, smaller power losses, and better voltage profile than that of PQ mode. Simulation analyses are established by Power System Analysis Toolbox (PSAT) running under MATLAB program.