Virtual synchronous generator variable inertia damping cooperative control method based on frequency deviation

Abstract

The invention relates to a virtual synchronous generator technology, in particular to a virtual synchronous generator variable inertia damping cooperative control method based on frequency deviation. The method comprises the following steps: acquiring absolute values of angular frequency deviation delta omega and angular frequency change rate of a virtual rotor of a virtual synchronous generator, and comparing the absolute values with corresponding thresholds; acquiring a new electrical angle through a virtual synchronous generator rotor motion equation, wherein values of virtual rotational inertia and a damping coefficient in the motion equation are adaptively changed according to delta omega; adjusting the electrical angle of the system according to an active-frequency control equation, and acquiring a voltage reference signal of a voltage and current loop through a three-phase sine wave generator according to the reference voltage amplitude output by the reactive-voltage loop; and enabling reference voltage and current signals of a voltage and current loop and capacitor voltage and inductive current in an output circuit of the virtual synchronous generator to pass through a PI regulator respectively, and then regulating system frequency through PWM (Pulse Width Modulation). According to the method, introduction of a high-frequency noise signal is avoided, and cooperative control of the virtual rotational inertia and the virtual damping is realized.

Description

technical field [0001] The invention belongs to the technical field of virtual synchronous generators, in particular to a variable inertia damping cooperative control method of virtual synchronous generators based on frequency deviation. Background technique [0002] Distributed power generation has obvious advantages such as environmental friendliness, wide range, and high flexibility. In recent years, it has attracted more and more attention from all walks of life. The microgrid integrates the resources of distributed power generation, and connects the power generation side and user loads through power electronic converters to form an independent power grid that is controllable as a whole. Compared with traditional large power grids, microgrids have some inherent characteristics: fast response capability, lack of inertia buffer and low overload capacity. The basic idea of ​​the virtual synchronous generator (VSG) is to make the grid-connected inverter simulate the charact...

AI Technical Summary

Problems solved by technology

Therefore, in order to obtain better system dynamic performance, and based on the idea that the frequency change rate is proportional to the reciprocal of the virtual moment of inertia, the frequency change rate is usually multiplied by a constant and added to the fixed moment of inertia to realize the adjustment of the moment of inertia, but Introducing a derivative term for frequency can lead to the introduction of high-frequency noise

In order to solve the above problems, it is necessary to add a low-pass filter after the frequency change rate, which will inevitably affect the dynamic characteristics of the system

[0004] Moreover, the application number is CN 201710970830.0, which is an invention patent titled "A Comprehensive Control Method for Adaptive Inertia Damping of Virtual Synchronous Generator". A low-pass filter is added later to filter out high-frequency signals, but this will affect the dynamic performance of the system and reduce the system phase angle margin

Images