Impedance adaptive power decoupling control method considering virtual synchronous machine power angle influence

Abstract

The invention relates to the field of distributed power generation, and aims at providing an impedance adaptive power decoupling control method considering the virtual synchronous machine power angleinfluence. The method comprises the steps that the fluctuating quantity Deltadelta of the power angle is estimated by using the output active power of a virtual synchronous machine, and then the virtual resistance value Rv and the virtual inductance value Xv of virtual impedance are calculated; and then the virtual impedance values Rv and Lv are added to an inverter voltage control loop, the obtained voltage given value EO* acts as the given signal of the internal loop voltage control loop, finally the output signal of internal loop control acts as the control signal of the inverter, and the internal loop is double closed loop control of voltage and current. The problem of power coupling caused by increasing of the power angle is considered, and the size of the virtual impedance value is autonomously changed when the output power angle fluctuates so as to realize power decoupling of the virtual synchronous machine. The influence of the power angle, i.e. the active power loop, on the reactive power control loop can be relieved, and the method has the stable, accurate and excellent control effect.

Description

technical field [0001] The invention relates to an impedance self-adaptive power decoupling control method considering the influence of the power angle of a virtual synchronous machine, and belongs to the fields of electrical engineering and distributed power generation. Background technique [0002] After entering the new century, the global energy shortage and environmental problems have become more and more serious. Under this background, renewable energy sources such as photovoltaics and wind energy have been extensively researched and developed. However, with the increasing penetration of distributed energy resources, the installed capacity of synchronous generators in the power system has relatively decreased. What is more serious is that the use of a large number of power electronic converters makes the system lack sufficient inertia and damping. The stability is challenged, thus, the virtual synchronous machine technology came into being. [0003] In the control of ...

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the defect that the power angle will cause the coupling effect of active power on reactive power when the virtual synchronous machine is connected to the grid, and propose an impedance adaptive power decoupling control method that considers the influence of the virtual synchronous machine power angle

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