VSG active control method for suppressing low-frequency oscillation of power system

Abstract

The invention relates to a VSG active control method for suppressing low-frequency oscillation of a power system, and the method comprises the steps: detecting the output electric angular speed of a virtual synchronous generator, and obtaining mechanical power; the mechanical torque is obtained through the mechanical power, and the electromagnetic torque is obtained through the measured electromagnetic power; the two damping branches form damping feedback to obtain damping torque; the variable quantity and the variation trend of the current output electric angular speed of the virtual synchronous generator serve as two input signals of an oscillation suppression algorithm, and rotational inertia is output; the mechanical torque, the electromagnetic torque, the damping torque and the rotational inertia are integrated into an active control loop of the virtual synchronous generator, and finally an electrical angle is obtained and participates in the virtual synchronous generator to suppress low-frequency oscillation of the power system. The problem that the low-frequency oscillation of the power system cannot be suppressed by the fixed rotational inertia in the traditional VSG is solved, and the active power low-frequency oscillation of the power system is suppressed by measuring the variable quantity and the change trend and changing the rotational inertia in time.

Description

technical field [0001] The invention belongs to the field of new energy grid connection, and in particular relates to a VSG active power control method for suppressing low-frequency oscillation of a power system. Background technique [0002] With the continuous development of my country's economy, the demand for energy continues to expand. However, the traditional non-renewable fossil energy is gradually facing exhaustion, and energy transformation is imperative. The intermittency, volatility and instability of new energy have brought huge challenges to the safe and stable operation of the power system. Among them, the grid connection of new energy cannot provide a large amount of inertia and damping for the power system like traditional synchronous generators. As a result, the "double high" power grid with a high proportion of clean energy and a high proportion of power electronic devices can easily cause low-frequency oscillations in the power system. How to make the grid...

AI Technical Summary

Problems solved by technology

[0004] The invention provides a VSG active power control method for suppressing low-frequency oscillations of power systems, and its purpose is to solve the problems of how to make new energy grid-connected with the inertia characteristics of traditional synchronous generators grid-connected, thereby improving the stability of power systems, suppressing low-frequency oscillations of power systems, etc.

Images