Gao Wenzhong

Stochastic Energy Scheduling in Microgrids Considering Uncertainties of Renewable Energy and Stochastic Load

Microgrid is a single controlled, independent power supply system consisting of a set of load, distributed generations, energy storage units and controllable devices. However, the inherent intermit and variability of renewable energy resources complicate microgrid operations. Meanwhile, more and more controllable loads are being integrated into the microgrid operation. In this paper, considering the stochastic and uncertainties of load demand and renewable energy power generation, a two-stage microgrid stochastic energy management model is established, and the constraints that the system model needs to meet are put forward. Then, the uncertainty problem of the model can be dealt with by the combination of scenario analysis and Monte Carlo simulation. Finally, the MATLAB optimization toolbox is used to solve the stochastic programming model. Compared with the deterministic model, the simulation results show the effective performance of the proposed approach.

Unified calculation of eigen-solutions in power systems based on matrix perturbation theory

Calculation of eigen-solutions plays an important role in the small signal stability analysis of power systems. In this paper, a novel approach based on matrix perturbation theory is proposed for the calculation of eigen-solutions in a perturbed system. Rigorous theoretical analysis is conducted on the solution of distinct, multiple, and close eigen-solutions, respectively, under perturbations of parameters. The computational flowchart of the unified solution of eigen-solutions is then proposed, aimed toward obtaining eigen-solutions of a perturbed system directly with algebraic formulas without solving an eigenvalue problem repeatedly. Finally, the effectiveness of the matrix perturbation based approach for eigen-solutions’ calculation in power systems is verified by numerical examples on a two-area four-machine system.