A stable grid voltage control method and system terminal for distributed photovoltaic grid-connected

Abstract

The invention belongs to the technical field of grid voltage control, and in particular relates to a distributed photovoltaic grid-connected stable grid voltage control method and system terminal. The stable grid voltage control method of distributed photovoltaic grid-connected includes the following steps: real-time collection of power quality parameters of the station photovoltaic grid-connected point and operating parameters of each grid-connected equipment; control of reactive power and voltage to adjust the reactive power output of the photovoltaic inverter , when the active power output of the photovoltaic inverter cannot reach the rated capacity, the remaining power capacity is used to provide reactive power support for the power grid; the energy storage voltage is controlled, and the photovoltaic grid-connected power is adjusted through charging and discharging of photovoltaic energy storage, and the energy storage is controlled to emit no energy. The active power is controlled by the reactive voltage. The present invention not only fully considers the active / reactive power adjustable margin of the photovoltaic inverter and effectively utilizes the photovoltaic energy storage coordinated control, but also achieves the purpose of improving the operating efficiency of the inverter and realizing peak load shaving and valley filling of the grid load, as well as the improvement of the photovoltaic power station. Optimize output and stabilize grid voltage control.

Description

technical field [0001] The invention belongs to the technical field of power grid voltage control, and in particular relates to a method for controlling the voltage of a distributed photovoltaic grid and a stable power grid voltage and a system terminal. Background technique [0002] One of the typical characteristics of the traditional distribution network is centralized power supply. The upper-level power transmission system provides a single-point power supply to the surrounding power distribution system. Without considering the transformer tap, due to the existence of line impedance, the closer The higher the voltage at the first end of the line, the lower the voltage near the end of the line. In order to ensure the power demand at the end of the line, the first end of the line is generally 10% higher than the rated value. However, after the distributed power supply is connected to the distribution network, the pattern of traditional single power supply radial power supp...

AI Technical Summary

Problems solved by technology

Existing reactive voltage control methods would require the end-of-line inverter to absorb too much inductive reactive power, even exceeding its apparent power limit

Moreover, the grid structure parameters are complex, and the dynamic response of some feedback algorithms is slow

These shortcomings restrict the application of reactive power and voltage control in inverter clusters

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