Study Of The Parallel Algorithm Of Micro-Grid Simulation Model

As the research hotspot of the current electric field, the implementation of transient simulation of the distributed energy resources powered micro-grid is considered to be of great scientific and engineering significance. Transient simulation of micro-grid is the foundation to understand the fast dynamic characteristics and to reveal the various related transient problems in the system. Around the theme of the the parallel algorithm of micro-grid simulation model, a method of establishing and solving hybrid micro-grid simulation system is proposed in this paper.Nodal analysis based electromagnetic simulation methodology is proposed, including that the primary simulation model micro-grid is transformed into a Norton equivalent form, and the system is transformed into linear equations by the use of the modeling method of electrical system based on the node equation. The Gauss elimination method is proposed to solve the linear equations. At the same time the sparsity and symmetry of coefficient matrix is put forward to improve the speed. The solving method of nonlinear elements is proposed, including compensation method and the piecewise linearization method.The implementation method for the component model of the micro-grid simulation system is researched. The distributed power supply, such as photovoltaic cell model is simplified, and convenient and easy mathematical model is set up. A detailed model of topology modeling method is used for the power electronic devices, so the power electronic devices in any form can be described by the combination of switch models. The modeling method for conventional elements such as general transformer, line, switch, load, and AC side power supply side is also put forward, especially considering the magnetic saturation and hysteresis of transformer magnetizing branch.In order to improve the simulation speed, the parallel algorithm of micro-grid system simulation is studied. The special small step model for the modeling of power electronic switch circuit is used so as to improve simulation efficiency, and the conventional simulation step is used for the other elements of electrical system and control system, and their interface is realized by interface transformer. On this basis, a parallel multi-rate electromagnetic transient simulation algorithm based on network division through transmission line is proposed, and the whole system can be decoupled and parallel solved. Finally, the correctness and effectiveness of the algorithm is verified through the modeling and simulation an example of a small low voltage photovoltaic micro-grid system.