| Traditional power system stability is achieved by having a large moment of inertia of large synchronous generator,the frequency stability is well maintained because the big moment of rotor inertia can fight against the variety of power system load-disturbance. But with more and more integration of distributed energy into the grid, the situation of the power system stability is undergoing big change, the rotating synchronous generator capacity ratio in the system is reduced.For distributed energy, mostly wind and solar energy, they are usually of small capacity, and the switching power supply itself has no rotational inertia at all, greatly reducing the stability of the power system anti-disturbance performance. On the other hand, for economic and technical reasons,the large synchronous generator can not work when the system load is small and below a certain limit, which the inertial energy of power system will lead to a more narrow edge, easy to produce high-frequency fluctuations.Virtual synchronous generator is propose to correct the problem, it is actually an inverter with a special control algorithm, where the algorithm integrates a synchronous generator model, so that the inverter is controlled in the way that its output may have the same characteristics as a rotary synchronous generator performance against the frequency fluctuation, so that it can help stabilize the system for frequency stability.In this paper, works are carried out on Matlab-Simulink modeling and simulation for virtual synchronous generator study, where the design of the inverter model, power system model, the electrical and mechanical part of the virtual synchronous generator, the prime mover controller and exciter controller are presented, and all aspects of the model are analyzed and verified then one by one, simulation result has given the correct response, the inverter is controlled to have a virtual synchronous generator output characteristic and features. |
PDF Full Text Request