Method and device for controlling virtual synchronous generator of photovoltaic power station

Abstract

The invention discloses a method and a device for controlling a virtual synchronous generator of a photovoltaic power station. Firstly, load shedding control is carried out on each photovoltaic generation unit participating in virtual synchronous generator control inside the photovoltaic power station; then, voltage, current and frequency signals at a grid-connected point of the photovoltaic power station are acquired; a virtual synchronous generator controller is used for realizing photovoltaic power station virtual synchronous generator control, and active and reactive power reference values of each photovoltaic generation unit are acquired; a power instruction obtained by the virtual synchronous generator controller is issued to each photovoltaic generation unit through a fiber network; and each photovoltaic generation unit receives the power instruction, the power reference value is tracked, and power control on the photovoltaic power station is realized. The above method realizes the photovoltaic power station virtual synchronous generator function, the safe and stable operation ability of the photovoltaic power station is enhanced, and the voltage and frequency control ability of the photovoltaic power station can be exerted.

Description

technical field [0001] The invention relates to the technical field of photovoltaic power generation systems, in particular to a control method and device for a virtual synchronous generator of a photovoltaic power station. Background technique [0002] With the continuous development of new energy power generation technology, in recent years, the proportion of new energy power generation (photovoltaic power generation, wind power generation, etc.) based on power electronic inverter interface in the power system is getting higher and higher. Major countries in the world have formulated their own plans for the development of new energy power generation. However, compared with the traditional synchronous generator power supply, the new energy power generation system based on the power electronic inverter interface has a faster response speed, decouples the response of the power generation system from the dynamic response of the power system, and has almost no moment of inertia...

AI Technical Summary

Problems solved by technology

However, compared with the traditional synchronous generator power supply, the new energy power generation system based on the power electronic inverter interface has a faster response speed, decouples the response of the power generation system from the dynamic response of the power system, and has almost no moment of inertia that is conducive to maintaining stable operation of the system And damping, a large number of its access will inevitably affect the dynamic characteristics of the power system, unable to provide the necessary voltage and frequency support for the power system, bring changes to the power system, and bring challenges to the stable operation and control of the power system

[0003] For new energy power generation systems with inverters connected to the grid, the control strategy generally adopted is current-type control based on the rotating coordinate system. This control method can realize the decoupling control of active and reactive power. Using this control method makes the new The energy generation system does not have rotational inertia and damping characteristics, which is not conducive to the stable operation of the system. The virtual synchronous generator control method can make the new energy generation system based on the inverter grid-connected have characteristics similar to synchronous generators

However, the photovoltaic grid-connected system in the prior art does not have the characteristics of a virtual synchronous generator. It would be time-consuming and laborious to transform the inverters of the existing photovoltaic units one by one, and since the inverters of each photovoltaic unit operate independently, other The mutual influence needs further research to ensure the operation performance of the entire photovoltaic power plant

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