The Fortescue Sequcence Components Research On Three-Phase Power Flow For Distribution Nework With Distributed Generators

With the growth in electricity demand and the shortage of traditional energy resources, this can be the accelerator of smart grid construction. However, as the key part to promote the development of smart grid, distribution network is in a long-term lagging. Most of all, the current grid structure and automation are difficult to match the smart distribution network. Consequently, the research core for the future distributed system may focus on planning and operation mode. Therefore, as the basic analysic tool, power flow calculation also requires further improvementAccording to the feature of hybrid power supply with one phase, two phases and three phases in the medium and low voltage distribution system, and the difficulty leaded by mass interconnection of distributed generators(DGs), this paper extends the traditional sequence components method and presents a multiphase power flow solution. In the approach, the transform relationship of sequence components among one-phase network, two-phase network and three-phase network is reformulated by using backward-forward sweeping algorithm (BFS). Furthermore, this paper provides distinguishing treatment using complete sequence components model to the singularity problem of admittance matrix appearing in particular transformer connections. And the DGs methods have fully considered various control strategies. Based on the anlysis, synchronous generator and asynchronous generator are modeled as constant of total three-phase output; photovoltaic system models takes solar radiation intensity and temperature into the maximum power point tracking control.This paper has tested six systems with several scales. Simulation results verify that:(1) The proposed method has stable convergence, which can solve the distribution network with various of DGs effectively. According to their control characteristics, DGs models are proved to be coincident with the reality. (2) The solution also shows robust convergence characteristics and efficient calculation with a promising prospect, especially suitable for the large-scale asymmetric distribution system.