Photovoltaic-energy storage power generation system and method based on virtual synchronous generator control

Abstract

The invention relates to a photovoltaic-energy storage combined operation power generation system based on a virtual synchronous generator control strategy and a control method thereof. The system istechnically characterized by comprising a photovoltaic-energy storage power generation system, a measuring component, a three-phase load and an alternating current power grid, wherein the photovoltaic-energy storage power generation system comprises a photovoltaic array, an energy storage battery, a photovoltaic direct current converter, a photovoltaic inverter and an energy storage inverter; andoutput ends of the photovoltaic inverter and the energy storage inverter are connected to a power grid alternating current bus. In the invention, the virtual synchronous generator control strategy isadopted by the energy storage inverter; and the operating characteristics of a synchronous machine with inertia and damping are adjusted by adjusting the energy storage device, so that the overall external characteristics of the photovoltaic and energy storage device are similar to the operating characteristics of the conventional synchronous machine. The own output power of the system can be adjusted for the photovoltaic output fluctuation and the load fluctuation, the frequency and voltage fluctuation of the photovoltaic system are stabilized, and the dynamic performance of a photovoltaic grid-connected plant is effectively improved.

Description

technical field [0001] The invention belongs to the technical field of new energy power generation, and relates to a photovoltaic-energy storage power generation system, in particular to a photovoltaic-energy storage power generation system and method based on virtual synchronous generator control. Background technique [0002] The output of photovoltaic power supply is limited and random due to the influence of weather and environment, which makes its characteristics different from traditional energy sources. The connection of photovoltaic grid-connected inverters to the AC bus will cause the frequency to change too fast, and the frequency fluctuations are out of control, thereby reducing electric energy. Quality has brought uncertainty and danger to industrial and agricultural production. With the gradual increase in the penetration rate of photovoltaic power generation, the threat to the power grid will gradually appear. Furthermore, distributed photovoltaic power source...

AI Technical Summary

Problems solved by technology

Although the VSG control strategy is also used on the inverter, the photovoltaic and energy storage are connected to the DC bus at the same time. Once the DC area fails, it will seriously affect the photovoltaic output and reduce the reliability of the system; moreover, it is not conducive to the new power supply. Join for expansion, poor scalability

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