Distributed photovoltaic grid-connected power generation control method for suppressing low-voltage feeder overvoltage

Abstract

The invention discloses a distributed grid-connected photovoltaic power generation control method for inhibiting overvoltage of a low-voltage feeder line. The method adopts a grid-connected photovoltaic power generation circuit and adjusts working modes of the circuit by detecting grid-connected point voltage in real time according to a grid-connected point voltage effective value Urms and current reactive power output magnitude. The method does not need power distribution network line modification, additional reactive compensation devices, load prediction or distributed photovoltaic connecting capacity limiting to prevent feeder line voltage from being out of limit, can improve the distributed photovoltaic permeability to low-voltage feeder lines and ensure voltage normal running of the low-voltage feeder lines by detecting grid-connected point voltage of distributed photovoltaic transducers in real time and setting different running modes according to running states to adjust control strategies of the transducers in real time, and has very wide market application prospect.

Description

technical field [0001] The invention belongs to the technical field of solar photovoltaic power generation control, and in particular relates to a distributed photovoltaic grid-connected power generation control method for suppressing the overvoltage of a low-voltage feeder. Background technique [0002] Photovoltaic power generation grid-connected systems are divided into photovoltaic power plants under the medium and high voltage system and distributed photovoltaic power generation under the low-voltage system according to the grid-connected voltage level. Distributed photovoltaic power generation mainly includes two common types: rural rooftop photovoltaic power generation and building-integrated photovoltaic power generation. However, when this intermittent distributed photovoltaic power generation system is incorporated into the low-voltage feeder on a large scale, especially the rural weak distribution network, it will change the power flow operation mode of the distrib...

AI Technical Summary

Problems solved by technology

However, when this intermittent distributed photovoltaic power generation system is incorporated into the low-voltage feeder on a large scale, especially the rural weak distribution network, it will change the power flow operation mode of the distribution network, causing the voltage on the feeder to rise or even exceed GB / Z19964- The range of voltage deviation (percentage of rated voltage) at the grid-connected place stipulated in the 2005 standard

In order to suppress the overvoltage on the feeder, the usual method is to limit the capacity of distributed photovoltaic access or install additional reactive power compensation devices. The former cannot fully utilize the capacity of the distributed photovoltaic power generation system, and the latter will increase costs.

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