Load sharing control in distributed generation system

Parallel operation of distributed generation system (DG´s) is a very useful method for solving the high power requirements. Under heavy load, the power system can become unstable exhibiting voltage drops that may lead to a voltage collapse. This paper addresses the load sharing control associated with the parallel operation of DG´s in order to maintain voltage stability. A general control strategy, involving modeling and control of parallel operating DG´s having non-linear dynamics, varying with load is developed. This control action regulates the voltage under imbalance condition of loads. Simulation results show that the proposed method is effective in displaying a reliable and robust control performance. Simulations are performed with a model composed of two DG´s units, two loads and wire impedances. Different cases like, power ratings and loads on both the units being equal, power rating and loads on both the units being unequal, and suddenly varying load conditions are taken up for analysis and simulation.