Optimal Sitting And Sizing Of Distributed Generation Planning In A Micro-grid System Integrated With Wind And Photovoltaic Power

As the demand for energy and environmental issues are becoming increasingly prominent, developing low-carbon economy and constructing ecological civilization to achieve sustainable development has aroused general interest. Exploiting clean non-polluting, renewable energy is an important strategic decision to challenges brought by energy and environment. Microgrid is able to integrate new energy power generation unit with storage unit and loads together, which can work on the grid-connect and stand-alone mode,easing pressure of large grid, maximizing the advantages of distributed power in aspects of economic, environmental and so on. In order to ensure microgrid operate reliably, economically and environmentally, generation’s type, location and size must be allocated reasonably.Considering the correlation between wind and photovoltaic(PV) power outputs and relevancies among different loads, the optimal sitting and sizing of microgrid generations in a microgrid work on the grid-connect and stand-alone mode is studied in this paper. The main work is presented as follows:(1) According to the correlations between distributed generations power outputs and relevancies among different loads of microgrid, Copula theory is introduced to establish probabilistic models for the power generation and total loads respectively. Historical simulation method is used to obtain value at risk of microgrid in order to realize the risk assessment of microgrid. Considering uncertainties, a low carbon price model is built based on Monte Carlo method.(2) Total costs of the microgrid under grid-connected mode is taken as objective function in which operating cost, low-carbon effect,electricity exchange between main grid and microgird is considered. Improved Invasive Weed Optimization(IIWO) is applied to find the optimal configuration. Results show that the algorithm has a good convergence and a strong global optimal capability. At last, a case study is presented to analyze correlation properties, economy, reliability and advantages of the algorithm.(3) Under the premise of meeting reliability constraints, a comprehensive economic cost function considering net loss expenses, penalties due to outage and waste of energy is established, the model and methodology is demonstrated though case studies simulated and calculated on a certain Offshore oilfield micro-grid system operated independently, IIWO is applied to find the optimal configuration, results verifies the validity of the proposed model and algorithm.