An Improved Newton Load Flow for Distributed Generation Based on Different Control Strategies

This paper presents an improved Newton Raphson load flow algorithm considering distributed generation (DG) based on their control strategies. Different control strategies for various DGs are firstly investigated and the load flow model for direct-driven wind generator is especially mentioned. Then, each kind of DGs, including photovoltaic, wind turbine, fuel cell and microturbine, is assigned a bus type according to its certain control strategy. An improved Newton Raphson load flow method for DGs is derived involving two unconventional bus types: PI and PQ (V). Numerical tests are carried out on the PG&E 69 bus system. Iteration performance shows that the suggested algorithm can maintain a quadratic convergence feature even if various DGs are mixed in the test system. In addition, a comparative study with back forward sweep method demonstrates a better computational efficiency of the proposed algorithm in handling network with multiple PV type DGs.