An online evaluation method for primary frequency modulation performance of a virtual synchronous machine

Abstract

The invention discloses an online evaluation method for the primary frequency modulation performance of a virtual synchronous machine, which belongs to the technical field of distributed power generation applications. The present invention can complete the online evaluation of the frequency modulation performance and frequency modulation output time of distributed generation virtual synchronous machines such as photovoltaics, wind power, and energy storage, and can judge whether the maximum output power of the VSG energy storage unit can reach the theoretical value determined by the control parameters. It can be judged whether the maximum frequency regulation time of the VSG can reach the time limit specified by the power grid. The invention will provide an effective evaluation method for evaluating the primary frequency modulation performance of the virtual synchronous machine.

Description

technical field [0001] The invention belongs to the technical field of distributed power generation, and in particular relates to an on-line evaluation method for the ability of a virtual synchronous machine to respond to power grid frequency fluctuations. Background technique [0002] With the prominence of energy shortages and environmental degradation worldwide, distributed generators (DGs) have been paid more and more attention due to their environmentally friendly and sustainable features, and a large amount of renewable energy has begun to be connected to the grid. However, unlike traditional synchronous generator sets, photovoltaic power generation has no rotating unit and cannot provide inertial support to the system. The rotating unit of wind power generation can only store a small amount of kinetic energy and cannot provide stable and effective inertial support for the system. With the continuous improvement of DG penetration rate, the proportion of installed capac...

AI Technical Summary

Problems solved by technology

Some scholars have derived the output response of the VSG energy storage unit when the new energy output fluctuates or the grid frequency fluctuates, without involving a frequency modulation process

Some researchers have analyzed the relationship between the output of the energy storage unit and the virtual inertia of the VSG, but none of them have given a reasonable evaluation method for the output capacity of the VSG

Moreover, with the emergence of the VSG self-adaptive mechanism, the parameters during the VSG operation are no longer fixed, and one-time offline calculation is no longer enough to make an accurate evaluation of the VSG function.

Images